MMA
The Biggest Upsets in UFC History
This article explores the biggest upsets in UFC history. We rank and analyse these bouts using the SportsBoom MetaScale.
Matt Serra def. Georges St-Pierre//Getty Images
Much like boxing, the Ultimate Fighting Championship has witnessed many upsets since its inception. Fans love to see shocking wins; there's just something so captivating about an underdog story and a big upset in combat sports when you least expect it.
In this article, we will rank and analyse the biggest upsets in UFC history using the SportsBoom MetaScale.
Methodology
The ranking of UFC upsets is based on:
Betting Odds (40%): Underdog odds at the time of the fight.
Title Stakes and Impact (30%): Effect on the division, fighter legacies, and championship status.
Fan Reaction and Shock Factor (20%): General sentiment and surprise value.
Historical Significance (10%): Influence on UFC history and long-term ramifications.
Sources Used:
Critical Consensus: Ranking the Biggest UFC Upsets
The critical consensus table includes the rankings from Tapology and UFC as well as the fight's outcome.
Critical Consensus Table
| Rank | Fight | Tapology Rank | UFC Rank | Outcome |
| 1 | Matt Serra vs. Georges St-Pierre (2007) | 1 | NR | Serra wins via KO/TKO, Punches |
| 2 | Julianna Peña vs. Amanda Nunes (2021) | 3 | 1 | Peña wins via Submission, Rear Naked Choke |
| 3 | Holly Holm vs. Ronda Rousey (2015) | 2 | NR | Holm wins via KO/TKO, Head Kick |
| 4 | Sean Strickland vs. Israel Adesanya (2023) | 4 | 2 | Strickland wins via Unanimous Decision |
| 5 | Michael Bisping vs. Luke Rockhold (2016) | 5 | NR | Bisping wins via KO/TKO, Punches |
| 6 | Chris Weidman vs. Anderson Silva (2013) | 6 | NR | Weidman wins via KO/TKO, Punches |
| 7 | Leon Edwards vs. Kamaru Usman II (2022) | 10 | 6 | Edwards wins via KO/TKO, Head Kick |
| 8 | Alexa Grasso vs. Valentina Shevchenko I | NR | 1 | Grasso wins via Submission, Rear Naked Choke |
| 9 | Nate Diaz vs. Conor McGregor (2016) | 8 | NR | Diaz wins via Submission, Rear Naked Choke |
| 10 | Bobby Green vs. Grant Dawson (2023) | NR | 3 | Green wins via KO/TKO, Punches |
SportsBoom Suggests
Matt Serra’s upset win over GSP remains the most shocking in UFC history due to its overwhelming odds, however, Julianna Peña defeating Amanda Nunes certainly comes close, considering Nunes’ total domination across multiple weight classes.
Recent upsets, like Sean Strickland’s win over Adesanya, showcase how unpredictable MMA remains even today; Strickland was overlooked by most, yet he totally outclassed Adesanya on his way to winning the belt.
Meanwhile, upsets like Holly Holm vs. Ronda Rousey highlights just how dangerous anyone can be in a fight. Rousey was thought to be undefeated because of her epic Judo skills. But, it only takes one shot to change the course of a fight, and that's exactly what Holm did.
SportsBoom MetaScale Table
| Rank | Fight | Betting Odds (40%) | Title Impact (30%) | Fan Reaction (20%) | Historical Significance (10%) | MetaScale Score |
| 1 | Matt Serra vs. Georges St-Pierre (2007) | 40 | 30 | 20 | 10 | 100 |
| 2 | Julianna Peña vs. Amanda Nunes (2021) | 38 | 30 | 20 | 8 | 96 |
| 3 | Holly Holm vs. Ronda Rousey (2015) | 35 | 25 | 20 | 8 | 88 |
| 4 | Sean Strickland vs. Israel Adesanya (2023) | 30 | 28 | 18 | 8 | 84 |
| 5 | Michael Bisping vs. Luke Rockhold (2016) | 30 | 20 | 18 | 6 | 74 |
| 6 | Chris Weidman vs. Anderson Silva (2013) | 28 | 20 | 18 | 6 | 72 |
| 7 | Leon Edwards vs. Kamaru Usman II (2022) | 28 | 20 | 18 | 5 | 71 |
| 8 | Alexa Grasso vs. Valentina Shevchenko I | 25 | 18 | 15 | 5 | 63 |
| 9 | Nate Diaz vs. Conor McGregor (2016) | 20 | 15 | 15 | 5 | 55 |
| 10 | Bobby Green vs. Grant Dawson (2023) | 15 | 10 | 15 | 5 | 45 |
The Biggest Upsets in UFC History: The Lowdown
In this section, we will provide a lowdown on all the fights featuring in the tables above. Here, you can read about key information regarding these bouts. This includes information such as the pre-fight odds as well as form or history heading into these fights.
1. Matt Serra vs. Georges St-Pierre (2007)
This ranks as the biggest upset in UFC history because during the prime years of Georges St-Pierre's illustrious career, he was knocked out with a clean hook from Matt Serra at UFC 69.
Heading into this bout, Serra was a +850 underdog; everyone was expecting GSP to wipe the floor with the American and continue his reign as the UFC welterweight champion.
2. Julianna Peña vs. Amanda Nunes (2021)
Julianna Pena punches Amanda Nunes//Getty Images
The greatest female MMA fighter of all time, Amanda Nunes, also suffered a shocking defeat in her prime years.
The Brazilian was on a 12-fight win streak heading into UFC 269, and everyone expected her to defend her UFC female bantamweight title in style. However, she was battered by a determined challenger, Julianna Peña. Peña's odds pre-fight were +700.
3. Holly Holm vs. Ronda Rousey (2015)
Nowadays, everyone points to Amanda Nunes and Valentina Shevchenko as the best women's UFC fighters ever. But, back in the 2010s, it was Ronda Rousey that was waving the flag for women's MMA.
Rousey had a plethora of devastating finishes to her name as she used her power and elite Judo to get fights to the mat. However, at UFC 193, she was on the receiving end of a brutal head kick from Holly Holm which ended the fight. Holm's odds were +830.
4. Sean Strickland vs Israel Adesanya (2023)
Heading into this bout at UFC 293, Sean Strickland was talking a lot of trash to the UFC middleweight champ, Israel Adesanya, and these mental warfare tactics evidently paid off.
Adesanya seemed too tense in this bout while Strickland was very loose, which helped him put on a counter-striking masterclass to win the 185-pounds title. The American's odds pre-fight were +400.
5. Michael Bisping vs. Luke Rockhold (2016)
This fight wasn't only one of the biggest upsets in UFC history, it also marked the first time a fighter from England claimed UFC gold. Michael Bisping and Luke Rockhold had a big rivalry, so for “The Count” to win the UFC middleweight belt in this fashion must've tasted even sweeter.
Bisping was a +600 underdog before his fight at UFC 199 when he KO'd Rockhold.
6. Chris Weidman vs. Anderson Silva (2013)
One of the greatest MMA fighters to ever do it, Anderson Silva’s 16-fight win streak and aura of invincibility came crashing down when Chris Weidman knocked him out at UFC 162.
While the Brazilian dominated the division for so long, Weidman was carving out an excellent start to his career going 9-0. The American was being touted as the next big thing, but he was still expected to be beaten by the more experienced Silva. Weidman's pre-fight odds were +240.
7. Leon Edwards vs. Kamaru Usman II (2022)
Leon Edwards lands a head kick to Kamaru Usman//Getty Images
Kamaru Usman was such a dominant UFC welterweight champion that he practically lapped the top 10 ranked fighters by defending the title against them more than once.
But in 2022, in Salt Lake City, he faced a determined underdog in Leon Edwards, an opponent who he fought way back in 2017. Since the first fight, both men, who were up-and-comers at that time, improved tremendously.
At UFC 278, Usman was dominating the challenger and looked on his way to winning an easy decision. However, in the final 60 seconds of the fight, Leon Edwards unleashed one of the best head kick knockouts in MMA history to win the belt and become only the second fighter from England to win a UFC title. His pre-fight odds were +400.
8. Alexa Grasso vs. Valentina Shevchenko I
Valentina Shevchenko went into UFC 285 with the most consecutive wins in UFC women's flyweight division history with nine, and seven of those were title defences.
Naturally, the Kyrgyzstan fighter was expected to defeat Alexa Grasso, even despite the Mexican being a very skilled fighter in her own right. Instead, Grasso put on a superb performance, dominating Shevchenko in striking and grappling, and she eventually got a submission win in the fourth round. Grasso's pre-fight odds were +500.
9. Nate Diaz vs. Conor McGregor (2016)
Back in 2015 and 2016, Conor McGregor made huge noise in the MMA world. After destroying Jose Aldo to become the UFC featherweight champion, he dared to be great and stepped up to welterweight to face Nate Diaz at UFC 196.
Fans flocked to see this bout because of the animosity between the two men, and we were all expecting a remarkable fight; it certainly didn't disappoint. After trading blow for blow at high pace, Diaz's cardio took over and won him the fight as he stunned McGregor and then submitted him on the ground.
Nate's pre-fight odds were +300. Whilst this isn't huge underdog odds, it was a huge upset because he stepped in and took the fight on short notice.
10. Bobby Green vs. Grant Dawson (2023)
Compared to the rest of the bouts on this list, this fight is certainly not up there in terms of big fights. Nevertheless, it is definitely up there in terms of the shock factor.
Bobby Green delivered one of the year’s biggest surprises by knocking out highly touted prospect Grant Dawson in just 33 seconds. His pre-fight odds were +750.
SportsBoom Suggests
Matt Serra’s upset win over GSP remains the most shocking in UFC history due to its overwhelming odds, however, Julianna Peña defeating Amanda Nunes certainly comes close, considering Nunes’ total domination across multiple weight classes.
Recent upsets, like Sean Strickland’s win over Adesanya, showcase how unpredictable MMA remains even today; Strickland was overlooked by most, yet he totally outclassed Adesanya on his way to winning the belt.
Meanwhile, upsets like Holly Holm vs. Ronda Rousey highlights just how dangerous anyone can be in a fight. Rousey was thought to be undefeated because of her epic Judo skills. But, it only takes one shot to change the course of a fight, and that's exactly what Holm did.
Jake Staniland is a sports writer who excels in covering a wide range of sports: football, combat sports and the NFL - All three subjects are his lifelong passions.
Jake is a boyhood Sheffield United fan, which is often a curse that he thanks his family for. His favourite Blades player ever is Billy Sharp
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