The 50 Greatest Upsets in UFC History

MMA is a sport that thrives on unpredictability. No matter how dominant a fighter may appear, there is always a chance for an upset. Throughout the history of the UFC, there have been numerous shocking victories that have left fans and experts alike in awe. In this article, we will countdown the 50 biggest upsets in UFC history, highlighting the fights that defied expectations and changed the course of the sport.

50. K.J. Noons Def. Nick Diaz Via First-Round TKO

In 2007, upstart promotion EliteXC created a 160-pound division and pitted Nick Diaz against K.J. Noons for the newly created title. Diaz, already a well-established fighter, was expected to easily defeat Noons and become one of the faces of the new promotion. However, Noons had other plans.

From the start of the fight, Noons landed a series of straight right hands that rocked Diaz. Despite Diaz's reputation for being tough and resilient, he couldn't withstand the barrage of punches. By the end of the first round, Diaz had massive gashes above both of his eyes, and the fight was called off. Noons shocked the world and left Diaz furious with the call.

49. Josh Thomson Def. Gilbert Melendez Via Unanimous Decision

In a highly anticipated battle of Bay Area lightweights, Gilbert Melendez was set to defend his Strikeforce title against Josh Thomson. Melendez was a heavy favorite, having only lost once in a competitive fight with Mitsuhiro Ishida the previous year. However, Thomson had other plans.

In June of 2008, the two met in a five-round classic that saw Thomson utilize leg kicks, wrestling, and boxing to win all five rounds. To the dismay of the crowd, Thomson kept his distance in the final minutes, knowing he had already won the fight. Melendez never stopped coming forward, but it wasn't enough to secure the victory. The two would later rematch, with Melendez reclaiming his title.

48. Kevin Burns Def. Roan Carneiro Via Second-Round Submission

At UFC 85, Kevin Burns, an unknown fighter making his UFC debut, faced off against experienced jiu-jitsu black belt Roan Carneiro. Burns was considered a massive underdog with little chance against the American Top Team veteran.

However, Burns showed his mettle by outworking Carneiro on the ground and holding his own against the decorated black belt. Halfway through the second round, Carneiro got on top, but Burns locked in a triangle choke, forcing Carneiro to tap. It was a shocking win for the relatively unknown fighter and a testament to the unpredictable nature of MMA.

47. Pete Spratt Def. Robbie Lawler Via Second-Round TKO

In 2003, Pete Spratt was a journeyman with a checkered resume and a 1-1 UFC record. He was expected to be another opportunity for the UFC to showcase their rising star, Robbie Lawler, who was 7-0 and trained with the same camp as Matt Hughes, the welterweight champion at the time.

At UFC 42, Spratt came out determined and sharp, using heavy leg kicks and superior athleticism to outwork the less experienced Lawler. In the middle of the second round, Lawler was forced to quit with his legs barely holding him up. Spratt's victory shocked the MMA world, but he turned down a shot at the welterweight champ, stating he wasn't ready for Hughes just yet.

46. Jason Lambert Def. Renato Sobral Via Second-Round TKO

Renato Sobral had earned himself a title shot against Chuck Liddell in the UFC, but his championship dreams were squashed after a minute and a half of an ill-advised game plan consisting of running straight at Liddell. Still, Sobral was a top ten light heavyweight and would be favored against most competition, especially Jason Lambert, who was coming off a knockout loss to Rashad Evans.

The two faced off at UFC 68, and in the second round of a fight Sobral was likely winning, they were stood up from the ground. Sobral attempted a reckless flying knee immediately after the fight restarted, but Lambert countered with a strong left hand, knocking Sobral out. It was a stunning upset that showcased the unpredictable nature of MMA.

45. Wanderlei Silva Def. Kazushi Sakuraba Via First-Round TKO

When Wanderlei Silva first met Kazushi Sakuraba, Silva was actually expected to lose. Sakuraba was considered by most to be the pound-for-pound best fighter in MMA at the time. However, Silva quickly recouped after being knocked down early in the fight and stopped Sakuraba with knees to the head on the ground. After the fight, Sakuraba presented Silva with his belt, and Silva offered Sakuraba a rematch.

44. Seth Petruzelli Def. Kimbo Slice Via First-Round TKO

Kimbo Slice was briefly thought to be a legitimate competitor in MMA. His aggressiveness, punching power, and massive following had him headlining EliteXC events. However, when Slice was set to take on the aging Ken Shamrock, Shamrock was forced to withdraw due to a cut, and Seth Petruzelli stepped in as a replacement.

In the opening seconds of the fight, Petruzelli dropped Kimbo with a single jab to the chin, shocking the MMA world. Kimbo was stopped in just 14 seconds, and the farce of his perceived dominance was exposed. It was a stunning upset that revealed the vulnerability of even the most hyped fighters.

43. Tim Sylvia Def. Andrei Arlovski Via First-Round TKO

At UFC 59, Andrei Arlovski was set to defend his UFC heavyweight title against Tim Sylvia in a rematch of a fight Arlovski had dominated and ended quickly one year earlier. Arlovski was the heavy favorite to keep his title, but Sylvia had other plans.

Early in the round, Arlovski dropped Sylvia with a right hand, but Sylvia showed his perseverance by standing back up and landing his own right hand, dropping the champion. A few shots on the ground, and Sylvia became the UFC heavyweight champion for the second time. The two would settle their rivalry with a rubber match only a few months later, with Sylvia earning a unanimous decision victory.

42. Chael Sonnen Def. Nate Marquardt Via Unanimous Decision

Nate Marquardt was the clear No. 1 contender for the UFC middleweight title, but he was given a fight with Chael Sonnen to stay busy until his title shot. At UFC 109, Sonnen showcased his wrestling skills, taking Marquardt down and punishing him for three rounds. Sonnen wrestled the title shot right out from under Marquardt, but in a shocking turn of events, Anderson Silva locked in a triangle choke, forcing Sonnen to tap late in the last round.

41. Marcio Cruz Def. Frank Mir Via First-Round TKO

In 2004, Frank Mir was the UFC heavyweight champion, but a motorcycle accident left him with a broken femur and torn ligaments in his knee. In 2006, Mir made his return to the Octagon against 1-0 Marcio Cruz. Mir looked sluggish and out of shape, and shockingly, he was stopped by strikes in the first round. It would be a few years before Mir regained his form, while Cruz never won in the UFC again.

40. Brett Rogers Def. Andrei Arlovski Via First-Round TKO

Andrei Arlovski had recently been knocked out in the first round by Fedor Emelianenko, but he was still considered to be on a higher level than the less experienced Brett Rogers. However, Rogers charged at Arlovski in the opening seconds, landing a hard right hand that forced the referee to stop the bout at just 22 seconds. Rogers used this win to secure a match against Fedor Emelianenko.

39. Nick Diaz Def. Robbie Lawler Via Second-Round TKO

In 2004, many believed Robbie Lawler would become the next UFC welterweight champion. When he faced Nick Diaz at UFC 47, it was assumed that Diaz would be left unconscious if the fight didn't go to the ground. However, Diaz surprised everyone by forcing a stand-up battle. Diaz landed a right hook from his southpaw stance in the middle of the second round, putting Lawler down and prompting the referee to call off the fight. The win put Diaz on the MMA map and showcased his striking skills.

38. Paulo Thiago Def. Josh Koscheck Via First-Round TKO

Just two months after a devastating first-round knockout of Yoshiyuki Yoshida, Josh Koscheck faced unheralded newcomer Paulo Thiago. Koscheck appeared frustrated to be facing such an unknown fighter, but he was still a huge favorite over Thiago at UFC 95. However, Thiago caught Koscheck with a right uppercut that left him dazed and falling to the ground. The referee quickly jumped in and stopped the fight, giving Thiago a shocking upset victory.

37. Jens Pulver Def. B.J. Penn Via Majority Decision

B.J. Penn began his career with three spectacular early first-round knockouts and was considered unbeatable. He was given a title shot against lightweight champion Jens Pulver, who was the underdog in the fight. Pulver survived Penn's early attacks and went on to win the last three rounds, retaining his title. Pulver would later lose a rematch against Penn in 2007.

36. Rashad Evans Def. Chuck Liddell Via Second-Round KO

In 2008, Rashad Evans faced off against the legendary Chuck Liddell. Most fans and experts expected Liddell to knock out Evans, but a shocking right hand from Evans dropped Liddell midway through the second round. The once-indestructible champion was left unconscious on the mat, and Evans used this victory to propel himself to a shot at the light heavyweight title, which he won.

35. Mark Coleman Def. Stephan Bonnar Via Unanimous Decision

Mark Coleman, the first-ever UFC heavyweight champion, had not achieved a victory in the promotion for almost ten years. At UFC 100, he faced Stephan Bonnar, known for his historic fight with Forrest Griffin in the finals of the first season of The Ultimate Fighter. Coleman used his wrestling to control Bonnar and punished him with punches on the ground, earning a unanimous decision victory. It was one of the highlights of the monumental event.

34. Pete Williams Def. Mark Coleman Via Overtime KO

At UFC 17, former heavyweight champion Mark Coleman was scheduled to face current champ Randy Couture in the main event. However, when Couture withdrew due to a training injury, he was replaced by Pete Williams, who was making his UFC debut. After a long first round that saw Coleman punish Williams on the ground, the fighters went into a three-minute overtime. Coleman was exhausted, and Williams took advantage by landing a barrage of punches and throwing a right head kick. Coleman ducked right into the kick and was immediately knocked out, resulting in one of the UFC's first head kick knockout highlights.

33. Frank Mir Def. Antonio Rodrigo Nogueira Via Second-Round TKO

Frank Mir faced Antonio Rodrigo Nogueira, considered one of the best heavyweights in MMA history. While Nogueira was the favorite, Mir showcased his improved striking and dropped Nogueira multiple times. In the second round, Mir finished Nogueira with punches on the ground, becoming the first fighter to stop the legendary Nogueira. It was a defining moment in Mir's career and showed that even the most revered fighters can be vulnerable.

This is just the beginning of our countdown of the 50 biggest upsets in UFC history. Stay tuned for the next installment, where we'll continue to explore the fights that shocked the world and forever changed the landscape of MMA.

15. Anderson Silva vs. Chris Weidman I

In one of the most shocking upsets in UFC history, Chris Weidman ended Anderson Silva's legendary reign as the middleweight champion. Silva was widely considered one of the greatest fighters of all time, and he had successfully defended his title 10 times before stepping into the Octagon against Weidman.

However, Weidman had other plans. In the second round of their fight at UFC 162, Weidman caught Silva with a left hook that sent the champion crashing to the canvas. Weidman pounced on Silva and delivered a flurry of punches, forcing the referee to step in and stop the fight.

This upset not only ended Silva's reign as champion but also marked the beginning of a new era in the middleweight division. Weidman's victory shocked the MMA world and solidified his place as a top contender in the division.

14. Matt Serra vs. Georges St-Pierre I

Georges St-Pierre was considered one of the most dominant champions in UFC history when he faced Matt Serra at UFC 69. Serra, a heavy underdog, had earned his title shot by winning the fourth season of The Ultimate Fighter.

In a stunning turn of events, Serra caught St-Pierre with a right hook early in the first round that sent the champion tumbling to the canvas. Serra followed up with a barrage of punches, forcing the referee to step in and stop the fight.

Serra's victory over St-Pierre is often regarded as one of the biggest upsets in UFC history. It not only dethroned a dominant champion but also proved that anything can happen in the world of MMA.

13. Holly Holm vs. Ronda Rousey

Ronda Rousey was the face of women's MMA and a dominant force in the bantamweight division when she faced Holly Holm at UFC 193. Holm, a former professional boxer, was seen as a significant underdog heading into the fight.

In a stunning upset, Holm outstruck and outmaneuvered Rousey throughout the fight. In the second round, Holm landed a devastating head kick that sent Rousey crashing to the canvas. Holm followed up with punches, and the referee stepped in to stop the fight.

Holm's victory over Rousey shocked the MMA world and ended Rousey's undefeated streak. It also solidified Holm as a top contender in the bantamweight division and showcased her impressive striking skills.

12. T.J. Dillashaw vs. Renan Barão

Renan Barão was on a 32-fight unbeaten streak and was considered one of the best pound-for-pound fighters in the world when he faced T.J. Dillashaw at UFC 173. Dillashaw, a heavy underdog, was expected to be another victim of Barão's dominance.

However, Dillashaw had other plans. In a masterful performance, Dillashaw utilized his superior footwork and striking to pick apart Barão throughout the fight. In the fifth round, Dillashaw landed a head kick followed by a series of punches, forcing the referee to step in and stop the fight.

Dillashaw's victory over Barão was a testament to his skill and showcased his ability to compete at the highest level. It also marked the beginning of Dillashaw's reign as the bantamweight champion.

11. Nate Diaz vs. Conor McGregor I

Conor McGregor was riding high as the featherweight champion when he faced Nate Diaz at UFC 196. Diaz, a late replacement for McGregor's original opponent, was seen as a significant underdog heading into the fight.

In a stunning turn of events, Diaz weathered an early storm from McGregor and began to find his rhythm in the second round. Diaz landed a hard punch that rocked McGregor, and he capitalized on the opportunity by taking the fight to the ground.

Diaz locked in a rear-naked choke, forcing McGregor to tap out and handing him his first loss in the UFC. Diaz's victory over McGregor shocked the MMA world and cemented his place as one of the sport's most exciting fighters.

10. Matt Hughes vs. Georges St-Pierre I

Matt Hughes was the dominant welterweight champion when he faced Georges St-Pierre at UFC 50. St-Pierre, a young and talented fighter, was seen as a significant underdog against the experienced champion.

In a shocking upset, St-Pierre caught Hughes with a left hook that sent him to the canvas. St-Pierre followed up with punches, forcing the referee to step in and stop the fight.

St-Pierre's victory over Hughes marked the beginning of his rise to greatness in the welterweight division. It also showcased his skill and potential as a future champion.

9. Randy Couture vs. Tim Sylvia

Tim Sylvia was the heavyweight champion and a dominant force in the division when he faced Randy Couture at UFC 68. Couture, a former champion, came out of retirement to challenge Sylvia for the title.

In a stunning upset, Couture utilized his superior wrestling and clinch work to neutralize Sylvia's size and reach advantage. Couture dominated the fight, winning a unanimous decision and becoming the first fighter in UFC history to win titles in two different weight classes.

Couture's victory over Sylvia shocked the MMA world and solidified his place as one of the sport's all-time greats. It also showcased his ability to compete with and defeat larger opponents.

8. Gabriel Gonzaga vs. Mirko Cro Cop

Mirko Cro Cop was one of the most feared strikers in the heavyweight division when he faced Gabriel Gonzaga at UFC 70. Gonzaga, a heavy underdog, was expected to be another victim of Cro Cop's devastating kicks.

In a stunning upset, Gonzaga caught Cro Cop with a head kick that sent him crashing to the canvas. Gonzaga followed up with punches on the ground, forcing the referee to step in and stop the fight.

Gonzaga's victory over Cro Cop shocked the MMA world and solidified his place as a top contender in the heavyweight division. It also marked the first time Cro Cop had been knocked out in his career.

7. Ronda Rousey vs. Holly Holm

Ronda Rousey was the undefeated champion and a dominant force in women's MMA when she faced Holly Holm at UFC 193. Holm, a former professional boxer, was seen as a significant underdog heading into the fight.

In a stunning upset, Holm utilized her superior striking and footwork to keep Rousey at bay throughout the fight. In the second round, Holm landed a head kick that sent Rousey crashing to the canvas. Holm followed up with punches, and the referee stepped in to stop the fight.

Holm's victory over Rousey shocked the MMA world and ended Rousey's undefeated streak. It also marked the beginning of Holm's reign as the bantamweight champion.

6. T.J. Dillashaw vs. Renan Barão II

T.J. Dillashaw shocked the MMA world when he defeated Renan Barão to win the bantamweight title at UFC 173. In their rematch at UFC on Fox 16, Dillashaw solidified his status as the champion with another dominant performance.

Dillashaw once again showcased his superior striking and footwork, picking apart Barão throughout the fight. In the fourth round, Dillashaw landed a head kick that dropped Barão, and he followed up with punches on the ground to secure the TKO victory.

Dillashaw's second victory over Barão solidified his place as the bantamweight champion and showcased his skill and dominance in the division.

5. Conor McGregor vs. Jose Aldo

Jose Aldo was the undefeated featherweight champion and considered one of the best pound-for-pound fighters in the world when he faced Conor McGregor at UFC 194. McGregor, known for his brash personality and knockout power, was seen as a significant underdog heading into the fight.

In a stunning upset, McGregor caught Aldo with a left hook just 13 seconds into the fight, knocking him out cold. McGregor's victory over Aldo marked the fastest finish in UFC title fight history and solidified his place as the featherweight champion.

McGregor's victory over Aldo shocked the MMA world and catapulted him to superstardom. It also ended Aldo's 10-year undefeated streak and marked the beginning of McGregor's reign as the face of the featherweight division.

4. Matt Serra vs. Georges St-Pierre II

In their rematch at UFC 83, Matt Serra once again shocked the world by defeating Georges St-Pierre to retain the welterweight title. Serra, a heavy underdog, had previously defeated St-Pierre in their first fight to win the championship.

In a back-and-forth battle, Serra showcased his striking skills and heart, going toe-to-toe with the highly skilled St-Pierre. In the second round, Serra landed a right hook that dropped St-Pierre, and he followed up with punches to secure the TKO victory.

Serra's second victory over St-Pierre solidified his place as the welterweight champion and marked one of the most remarkable comebacks in UFC history.

3. Holly Holm vs. Ronda Rousey II

In their rematch at UFC 193, Holly Holm once again shocked the world by defeating Ronda Rousey to retain the bantamweight title. Holm, a heavy underdog, had previously defeated Rousey in their first fight to become the champion.

In a dominant performance, Holm utilized her superior striking and footwork to keep Rousey at bay throughout the fight. In the second round, Holm landed a head kick that sent Rousey crashing to the canvas. Holm followed up with punches, and the referee stepped in to stop the fight.

Holm's second victory over Rousey solidified her place as the bantamweight champion and marked the end of Rousey's reign as the undefeated champion.

2. Nate Diaz vs. Conor McGregor II

In their highly anticipated rematch at UFC 202, Nate Diaz once again shocked the world by defeating Conor McGregor. McGregor, seeking revenge for his loss to Diaz in their first fight, was seen as the favorite heading into the rematch.

In a back-and-forth battle, Diaz showcased his durability and grappling skills, taking McGregor down and controlling him on the ground. Diaz also landed significant strikes on the feet, bloodying McGregor's face. The fight went the distance, and Diaz was awarded a majority decision victory.

Diaz's second victory over McGregor solidified his place as one of the sport's most exciting fighters and showcased his ability to compete with and defeat the best in the world.

1. Chris Weidman vs. Anderson Silva II

In the main event of UFC 162, Chris Weidman shocked the world by defeating Anderson Silva to become the middleweight champion. Silva, widely regarded as one of the greatest fighters of all time, had successfully defended his title 10 times before facing Weidman.

In a shocking turn of events, Weidman caught Silva with a left hook in the second round that sent the champion crashing to the canvas. Weidman followed up with punches, and the referee stepped in to stop the fight.

Weidman's victory over Silva marked the end of Silva's reign as the middleweight champion and solidified Weidman as one of the top fighters in the division.