20 Biggest Upsets In UFC History (Fight Videos Included!)

Mixed martial arts, particularly in the UFC, has always been a sport ripe with surprises and dramatic turnarounds. 

Upsets are a fundamental part of its allure, offering moments of awe and disbelief as underdogs triumph against all odds.

This article delves into the 20 biggest upsets in UFC history, showcasing bouts where the unexpected became reality.

20 Biggest Upsets In UFC History

As upsets are subjective, this article on the 20 biggest upsets in UFC history is presented in chronological order. 

This allows you to easily see how these stunning fights have contributed to the rich tapestry of UFC history, highlighting the unpredictable nature of MMA.

1. Pete Williams (W) vs. Mark Coleman – May 15, 1998 (UFC 17)

In an era where the sport was still evolving, this fight stood out for its drama and historical significance.

Mark Coleman, a dominant wrestler and two-time UFC tournament champion, was a massive favorite due to his unrivaled strength, ground-and-pound, and how wrestling was the prevailing strategy in MMA.

Pete Williams, a lesser-known fighter from the respected Lion’s Den team, faced Coleman in a match that reflected the sport’s “dark days”.

With minimal pay, less regulation (including the allowance of shoes and steroids), and the sport still finding its footing, fighters represented not just themselves but their gyms, fighting styles, and countries.

The fight, which included a 10-minute first round, showcased the raw and unrefined nature of early MMA. Techniques like wall walking hadn’t been developed yet, and teams guarded their knowledge closely.

Williams’ stunning head-kick knockout of Coleman was groundbreaking and marked a pivotal moment in MMA history that inspired many fans and highlighted the unpredictability and excitement of the sport.

2. Jens Pulver (W) vs. B.J. Penn – January 11, 2002 (UFC 35)

This bout featured Jens Pulver, the reigning UFC Lightweight Champion, defending his title against B.J. Penn, a rising star with a formidable Brazilian jiu-jitsu background. 

Penn entered the fight as a favorite due to his grappling prowess and quick rise in the division, having won his previous three UFC fights by first-round stoppage.

Pulver, despite being the champion, was seen as the underdog. He was known for his boxing skills and toughness but wasn’t expected to cope with Penn’s ground game. 

The fight went the distance, showcasing Pulver’s resilience and ability to neutralize Penn’s grappling. 

Pulver’s victory by majority decision was a significant upset, as many had anticipated Penn’s coronation as the new champion.

3. B.J. Penn (W) vs. Matt Hughes – November 20, 2004 (UFC 46)

B.J. Penn moved up a weight class to challenge Matt Hughes for the UFC Welterweight Championship. 

Hughes was a dominant champion in the welterweight division, known for his wrestling prowess and physical strength. He was on a 13-fight winning streak and was widely considered unbeatable in his weight class.

Penn, primarily known as a lightweight fighter and a Brazilian jiu-jitsu specialist, was seen as a significant underdog due to his size and strength disadvantage. 

However, the fight took a surprising turn when Penn managed to take Hughes down and control him on the ground, a feat rarely seen against Hughes. 

In the first round, Penn capitalized on his superior jiu-jitsu skills and secured a rear-naked choke, submitting Hughes and becoming the new UFC Welterweight Champion.

This victory was one of the biggest upsets in UFC history because it defied weight-class norms and expectations.

4. Joe Lauzon (W) vs. Jens Pulver – September 23, 2006 (UFC 63)

Jens Pulver, a former UFC lightweight champion, was making his return to the UFC after a four-year absence. He was widely respected for his boxing skills and experience and was expected to make a triumphant return.

Joe Lauzon, on the other hand, was relatively unknown and making his UFC debut. He had fought in smaller organizations and didn’t have the same level of exposure or experience as Pulver.

The fight ended abruptly and shockingly, just 48 seconds into the first round when Lauzon landed a clean left hook that knocked Pulver out.

Lauzon’s knockout win instantly put him on the map in the UFC lightweight division and is remembered as a classic example of an underdog defying the odds.

5. Matt Serra (W) vs. Georges St-Pierre – April 7, 2007 (UFC 69)

In what is often regarded as the biggest upset in UFC history, Matt Serra defeated Georges St-Pierre (GSP) to win the welterweight championship. 

GSP, a dominant champion known for his well-rounded skills, was heavily favored to win, with betting odds placing him as a significant favorite (GSP was around a -1300 favorite, while Serra was a +850 underdog).

Serra, who had earned his title shot through The Ultimate Fighter 4, was considered a long shot. 

However, Serra capitalized on an opening in the first round, landing powerful strikes that overwhelmed GSP and led to a TKO victory.

This fight is a prime example of the unpredictability in MMA, where underdogs can defy the odds and achieve remarkable victories.

6. Gabriel Gonzaga (W) vs. Mirko Cro Cop – April 21, 2007 (UFC 70)

In a stunning upset, Gabriel Gonzaga defeated the heavily favored Mirko ‘Cro Cop’ Filipovic, who was known for his devastating head kicks, and entered the fight with betting odds at -500. 

Gonzaga, a Brazilian jiu-jitsu specialist and a significant underdog at +400, achieved the unexpected by knocking out Cro Cop with a stunning roundhouse kick in the first round, ironically using Cro Cop’s signature technique against him.

Adding to the fight’s significance, a title shot against then-heavyweight champion Randy Couture was on the line, heightening the stakes.

7. Forrest Griffin (W) vs. Mauricio ‘Shogun’ Rua – September 22, 2007 (UFC 76)

Mauricio Rua was highly regarded as one of the best light heavyweight fighters in the world, having established a formidable reputation in PRIDE Fighting Championships with his aggressive Muay Thai and Brazilian jiu-jitsu skills, and becoming the 2005 PRIDE Middleweight Grand Prix Champion.

Griffin (+250), while a fan favorite due to his heart and tenacity, wasn’t expected to prevail against the much-hyped UFC newcomer Rua. 

The odds were in favor of Rua (-350), who was anticipated to make a dominant debut in the UFC by breezing past Griffin.

However, Griffin displayed remarkable resilience, takedown defense, and cardio, ultimately tiring Rua and submitting him with a rear-naked choke in the third round.

8. Frankie Edgar (W) vs. BJ Penn – April 10, 2010 (UFC 112)

Frankie Edgar’s victory over BJ Penn at UFC 112 stands as one of the biggest upsets in UFC history, especially considering the betting odds, which had Edgar as a +525 underdog and Penn as a -750 favorite. 

Penn, the reigning UFC lightweight champion at the time, was renowned for his Brazilian jiu-jitsu mastery, striking ability, and incredible takedown defense, making him a dominant figure in the division.

Despite Edgar’s reputation for his speed and endurance, few anticipated he could overcome Penn, who had been a formidable titleholder. 

However, Edgar’s performance defied the odds. He executed a strategic fight plan, utilizing his quick movement and superior boxing to outmaneuver Penn over five rounds.

9. Chris Weidman (W) vs. Anderson Silva – July 6, 2013 (UFC 162)

Chris Weidman’s victory over Anderson Silva at UFC 162 is regarded as one of the most shocking upsets in UFC history. 

Silva, at the time, was the UFC middleweight champion and considered one of the greatest mixed martial artists ever. 

He had defended his title 10 times and was on a 16-fight winning streak, known for his striking precision and elusive movement.

Weidman, a rising contender with a strong wrestling background and undefeated record, was seen as a formidable opponent but still a significant underdog (+165). The betting odds reflected Silva’s dominance at -215.

The fight ended in the second round when Weidman caught Silva with a left hook as Silva was taunting and dropping his guard, a tactic he had famously used to frustrate opponents. 

Weidman’s knockout victory stunned the MMA world, as it was the first time Silva had been defeated in the UFC, and it was his first defeat since 2006.

This upset was monumental not just for the way it ended but for what it represented – the end of Silva’s long reign as champion and the rise of a new era in the middleweight division.

10. TJ Dillashaw (W) vs. Renan Barão – May 24, 2014 (UFC 173)

Renan Barão, the UFC bantamweight champion, was on a 32-fight unbeaten streak and a formidable figure in the division, with odds favoring him at -425. Dillashaw, with odds at +305, was considered a significant underdog.

Despite the odds, Dillashaw showcased a spectacular performance, surprising many with his footwork, striking, and agility. He dominated Barão throughout the fight, culminating in a TKO victory in the fifth round via head kick and punches.

Dillashaw’s triumph over Barão marked a major shift in the bantamweight division and highlighted the importance of strategy and adaptability in MMA, proving that even champions considered near-invincible could be dethroned.

11. Holly Holm (W) vs. Ronda Rousey – November 14, 2015 (UFC 193)

Holly Holm’s victory over Ronda Rousey at UFC 193 is one of the most stunning upsets in UFC history. Rousey, the reigning bantamweight champion, was a dominant figure in the UFC and a global superstar.

She entered the fight with overwhelming odds in her favor at -1250, with a 12-0 undefeated record and having dispatched previous opponents with relative ease, mostly in the first round.

Holm, a former professional boxer and kickboxer, was a significant underdog at +825. Despite her striking credentials, many doubted her ability to overcome Rousey’s judo prowess and aggressive fighting style.

However, the fight unfolded in stark contrast to expectations. Holm maintained distance with her superior striking, effectively neutralizing Rousey’s attempts to close in. 

In the second round, Holm landed a perfectly executed head kick, knocking Rousey out and ending her unbeaten streak. 

Holm’s victory demonstrated the importance of striking skills in women’s MMA and marked the end of Rousey’s reign as the seemingly invincible champion due to her incredible grappling skills.

12. Conor McGregor (W) vs. Jose Aldo – December 12, 2015 (UFC 194)

The fight between Conor McGregor and Jose Aldo at UFC 194, though not a traditional upset in terms of betting odds, is one of the biggest upsets in UFC history. 

McGregor, a slight favorite at -135, faced Aldo, who was a +105 underdog. Aldo had been the reigning featherweight champion in the WEC and UFC, was on an 18-fight win streak, undefeated in 10 years, and was widely regarded as the greatest featherweight in MMA history.

His dominance in the division had been unquestioned, and he was known for his striking precision and defensive skills.

McGregor, known for his striking power, speed, precision, and psychological warfare, had rapidly risen to prominence in the UFC. 

The fight was highly anticipated, with McGregor’s bold predictions and charismatic persona building immense hype.

The outcome was stunning – McGregor knocked out Aldo in just 13 seconds with a perfectly timed left straight, the fastest knockout in UFC title fight history. 

This victory wasn’t just an upset in terms of Aldo’s long-standing reign and McGregor’s relatively shorter tenure in the UFC, but also in the manner it was achieved – with McGregor claiming that he’d knock out Aldo in the first round.

13. Nate Diaz (W) vs. Conor McGregor – March 5, 2016 (UFC 196)

Conor McGregor entered his fight against Nate Diaz at UFC 196 as the featherweight champion and a massive favorite, riding a wave of hype following his stunning victory over Jose Aldo. 

McGregor, known for his striking power and psychological dominance, was expected to continue his winning streak, even as he moved up two weight classes for this bout (145 to 170).

Diaz, a seasoned fighter with a reputation for durability and skill, accepted the fight on short notice, stepping in for the injured Rafael dos Anjos. 

Despite being a +310 underdog, Diaz’s natural fit at welterweight, coupled with his excellent cardio, proficient boxing, and renowned toughness, presented a unique challenge to McGregor.

The fight unfolded with Diaz absorbing McGregor’s early attacks before turning the momentum in his favor. 

Utilizing his boxing skills and resilience, Diaz stunned McGregor in the second round and then secured a victory with a rear-naked choke following a takedown attempt by McGregor.

This upset not only halted McGregor’s meteoric rise but also highlighted the complexities of weight class changes in MMA, showcasing how factors like size, endurance, and experience can dramatically influence the outcome of a fight.

14. Michael Bisping (W) vs. Luke Rockhold II – June 4, 2016 (UFC 199)

Luke Rockhold, the defending middleweight champion, entered the fight as a massive favorite with odds at -1050. He had previously defeated Bisping and was known for his well-rounded skills and elite kickboxing.

Michael Bisping, a veteran of the sport and a +600 underdog, took the fight on 17 days’ notice, stepping in for an injured Chris Weidman. 

Despite his experience and status as a contender, few expected Bisping to pose a serious threat to Rockhold’s title reign, especially considering their first encounter where Rockhold dominated and secured a submission victory.

However, the fight took an unexpected turn. Bisping, showcasing remarkable striking, managed to catch Rockhold with a left hook early in the first round, followed by another that knocked the champion down. 

Bisping then quickly capitalized with a flurry of punches, leading to a knockout victory and becoming the UFC middleweight champion and first British UFC champion.

15. Rose Namajunas (W) vs. Joanna Jędrzejczyk – November 4, 2017 (UFC 217)

Joanna Jędrzejczyk, the reigning strawweight UFC champion, entered the fight as a significant favorite with odds at -450.

She was known for her elite Muay Thai striking precision and dominant performances and had successfully defended her title five times, leading many to believe she was nearly unbeatable in the division.

Rose Namajunas, a +350 underdog, was respected for her skills but wasn’t expected to dethrone the dominant champion. 

However, Namajunas, showing composure and striking ability, managed to stun Jędrzejczyk early in the first round with a left hook and followed up with a flurry of punches, leading to a TKO victory.

This upset was significant for several reasons. It ended Jędrzejczyk’s dominant reign as champion and showcased Namajunas’ rapid evolution as a fighter.

16. Henry Cejudo (W) vs. Demetrious Johnson II – August 4, 2018 (UFC 227)

Demetrious Johnson, the reigning flyweight champion, wasn’t just dominant but was also on his way to solidifying his status as one of the greatest mixed martial artists of all time.

He had defended his title a record 11 times and was known for his exceptional well-roundedness, perfect technique, and high fight IQ.

Cejudo, an Olympic gold medalist in wrestling, had improved significantly since his first loss to Johnson. However, he entered the rematch as a considerable underdo (+400). 

Johnson’s previous dominance and technical prowess in their first fight led many to believe that Cejudo would again be knocked out.

The fight, however, was a closely contested battle. Cejudo showcased his evolution as a mixed martial artist, utilizing his wrestling base effectively and engaging in back-and-forth striking exchanges with Johnson.

In a split decision victory, Cejudo ended Johnson’s historic title reign, capturing the flyweight championship. Any fighter Johnson loses to is a huge upset because he’s so good that no one expects him to lose.

It was even more of an upset because most fans believed that Demetrious Johnson had won this fight and that the judges had got it wrong.

17. Julianna Peña (W) vs. Amanda Nunes – December 11, 2021 (UFC 269)

Amanda Nunes, the reigning bantamweight and featherweight champion, is the greatest female fighter in MMA history. 

Her dominance across two weight classes had been nearly unchallenged, and she entered this fight as a heavy favorite (-1100).

Peña, on the other hand, was seen as a significant underdog (+600). Despite her determination and grappling skills, few predicted she’d be the one to dethrone Nunes, who’d convincingly defeated some of the biggest names in the sport.

The fight, however, defied all expectations. Peña showed incredible resilience and a strategic approach, absorbing Nunes’ early attacks and then turning the tide with her striking. 

In the second round, Peña’s relentless pressure and non-stop boxing combinations began to wear Nunes down, leading to a shocking submission victory via rear-naked choke.

This upset was monumental as it represented the end of Nunes’ long reign as the seemingly invincible champion. It showed she was human and could have off days.

18. Leon Edwards (W) vs. Kamaru Usman II – August 20, 2022 (UFC 278)

Leon Edwards’ victory over Kamaru Usman in their second meeting is a standout upset in UFC history, not just for the betting odds, which had Usman as a -300 favorite and Edwards at +250, but more so for the dramatic turn of events in the fight. 

Usman, the reigning welterweight champion, was known for his dominant wrestling and striking abilities.

Edwards, despite being a skilled and respected fighter who hadn’t lost in 7 years since his first fight against Usman, wasn’t expected to overcome Usman, particularly given the way Usman was dominating the fight. 

However, in a stunning twist, Edwards landed a perfectly executed roundhouse head kick with just about a minute left in the final round, knocking Usman out cold. 

This knockout was not only spectacular but also highly unexpected, given the flow of the fight until that point. It highlighted the importance of focus in MMA, no matter how one-sided a fight might seem.

19. Alexa Grasso (W) vs. Valentina Shevchenko – March 5, 2023 (UFC 285)

In a stunning upset at UFC 285, Alexa Grasso defeated the heavily favored Valentina Shevchenko, the reigning flyweight champion. 

Shevchenko, with odds at -800, was considered one of the most dominant fighters in women’s MMA, known for her exceptional Muay Thai striking and comprehensive skill set. 

She had defended her title multiple times, showcasing her prowess and versatility in the octagon.

Grasso, a significant underdog at +550, wasn’t expected to unseat the champion, despite her durability and boxing ability.

However, Grasso displayed remarkable striking, agility, and tactical acumen, outstriking Shevchenko in ways that few previous opponents had managed.

The victory was a major career milestone for Grasso, who managed to retain the title when the two met again at UFC Fight Night 227, via a dubious draw.

20. Israel Adesanya vs. Sean Strickland – September 2023 (UFC 293)

Israel Adesanya, known for his striking prowess and as one of the top fighters in the division, entered the fight as a heavy favorite with odds heavily in his favor (-650). 

His reputation for technical striking and fight IQ had made him a dominant figure in the middleweight category.

Strickland, a +450 underdog, wasn’t widely expected to pose a serious challenge to Adesanya’s reign, especially considering he accepted to fight on a month’s notice.

Despite this, Strickland showcased a strategic and disciplined approach, managed to neutralize Adesanya’s striking and unsettle him with forward pressure, constant jabs, and teeps. 

he fight served as a reminder of the ever-present potential for surprises in MMA, where even highly favored champions can be unseated by well-prepared challengers.