With UFC 299 approaching, let’s take a moment to go back through the archives and review some of the biggest upsets in UFC history. Inside the Octagon, anything can happen at any moment, making MMA one of the world’s most breathtaking sports.

What is the biggest UFC upset ever?

Most UFC fans will give you the same answer to this question.

Matt Serra’s 2007 defeat of one of the UFC’s biggest stars at the time, Georges “Rush” St. Pierre, remains the single greatest upset in the history of the sport. St. Pierre was 13-1 at the time, having suffered only one defeat (in 2004 to Matt Hughes) early in his career.

After losing that 2004 fight, St. Pierre had come back and demolished Hughes in November 2006. That set up his fight with Matt Serra in April 2007. Nobody gave the underdog a shot, but Serra beat some of the biggest UFC upset odds, since St. Pierre had been favored by a line of as much as -1300 to win.

Serra not only scored the upset but also did so via knockout in the very first round of the fight.

The 10 Biggest Upsets in UFC History

10. UFC 217: Rose Namajunas vs. Joanna Jedrzejczyk - Main Card

Date: Nov. 4, 2017
Closing UFC Betting Lines: Namajunas +500, Jedrzejczyk -700
Final Result: Rose Namajunas by KO/TKO Punches

UFC 217 featured a highly anticipated showdown between undefeated champion Joanna Jedrzejczyk and her challenger, a rising fighter nicknamed “Thug” Rose Namajunas. It would turn out to be one of the biggest UFC underdog wins in history.

Namajunas had come through Season 20 of the Ultimate Fighter competition in 2014 before making her debut in the UFC in 2015 with a rear naked choke win over Angela Hill. She then achieved a similar victory against Paige VanZant. She won four of her first five UFC fights to swiftly earn a title fight against Jedrzejczyk.

Despite her rise, Namajunas was still a heavy underdog against Jedrzejczyk, who was 14-0 at the time. Jedrzejczyk had just successfully defended her UFC strawweight title for the fifth straight time, marking one of the most impressive title runs in the history of the program.

Four of those five straight Jedrzejczyk wins had come via unanimous decision, but Namajunas stepped into the Octagon and went right on the attack. A fierce left hook sent Jedrzejczyk to the mat, and Namajunas swiftly finished her off to the sound of Daniel Cormier yelling “THUG ROSE” into the mic.

It remains one of the most epic underdog stories in the UFC, and was made even more impressive when Namajunas defended her title in the rematch at UFC 223. In fact, she handed Jedrzejczyk both the first and second losses of her UFC career.

9. UFC 196: Miesha Tate vs. Holly Holm - Co-Main Event

Date: March 5, 2016
Closing UFC Betting Lines: Tate +260, Holm -320
Final Result: Miesha Tate by Submission (Rear Naked Choke)

The undefeated Holly Holm, who was 10-0 at the time, had just achieved a remarkable upset victory over the UFC poster girl Ronda Rousey, which led to her first title defense against Miesha Tate at UFC 196.

Tate was familiar with Rousey, having faced her in losses during their time at Strikeforce and in the early stages of women's UFC at UFC 168. Tate’s record stood at 16-5 by the time she met Holm as a title challenger, and she had won four straight fights.

Tate wasn’t the biggest underdog on this list going into the fight, but by the time the fifth round began, she was struggling for answers. Tate had controlled the second round and had a shot at a submission. However, she was unable to finish it and allowed Holm to regain control in Rounds 3 and 4.

Then, in the fifth round, with barely two minutes remaining in the fight, Tate managed to secure another takedown, taking control of Holm's back and executing a perfect rear naked choke to steal the title away.

8. UFC 196: Nate Diaz vs. Conor McGregor - Main Event

Date: March 5, 2016
Closing UFC Betting Lines: Diaz +350, McGregor -450
Final Result: Diaz by Submission (Rear Naked Choke)

The Diaz brothers are fighters, and quitting has never been an option for them. Nate Diaz’s display against Conor McGregor is one of the best examples of refusing to lie down, as he fought back to stun McGregor with a submission victory at UFC 196.

McGregor was the heavy favorite entering the fight. He had a 19-2 record with an impressive seven-match winning streak in his UFC fights leading up to the showdown with Diaz. He had beaten the likes of Max Holloway, Dustin Poirier, and Jose Aldo during the seven-fight run.  

The fight started out as expected, and McGregor made light work of Diaz’s face in the early stages. By the end of Round 1, McGregor had busted Diaz’s face wide open, and he was badly bloodied when the bell rang.

The difference for McGregor here, compared to his previous opponents, was that Nate Diaz never gives up. In Round 2, Diaz returned ready to endure more punishment -- showing his opponent that he was unlike any other fighter McGregor had faced.

Sure enough, Diaz sustained the blows, and then caught McGregor with a strong left, stunning him just long enough to open the door. Diaz quickly took on the role of aggressor, prompting McGregor to resort to a takedown as he ran out of options.

Diaz capitalized on this takedown move, mounting and then choking McGregor into a submission. He ended the run of “The Notorious” and handed him his first UFC loss

7. UFC 162: Chris Weidman vs. Anderson Silva - Main Event

Date: July 6, 2013
Closing UFC Betting Lines: Weidman +195, Silva -240
Final Result: Weidman by KO/TKO Punches

Chris Weidman came into his title challenge against the legendary Anderson Silva with an impressive 9-0 record, having quickly fought his way up through the middleweight division.

Meanwhile, Silva was in the latter years of his career at this point, yet he remained a clear favorite over his challenger, despite being almost a decade older.

The Brazilian hadn’t lost in the Octagon since 2006. He had been on an iconic run that took him from 16-4 to 32-4, including 10 straight successful title defenses.

Many had tried and failed to take down “The Spider,” perhaps leading him to become overly confident before the Weidman fight. Throughout the fight, Silva was showing off --playing to the crowd and dancing around his opponent as if he was involved in some sort of exhibition bout.

He never took Weidman seriously, and in the second round, Weidman made him pay for it. Silva was evading punches with his hands by his side, simply dodging them with his head movements, until he misjudged one.

Weidman caught him once, and then knocked him clean out with a well-timed shot to the chin, ending the legend’s title run in stunning fashion.

6. UFC 293: Sean Strickland vs. Israel Adesanya - Main Event

Date: Sept. 9, 2023
Closing UFC Betting Lines: Strickland +470, Adesanya -650
Final Result: Sean Strickland by Unanimous Decision

Israel Adesanya had just reclaimed his UFC middleweight title from Alex Pereira in their rematch at UFC 287. His next challenger would be Sean Strickland, a fighter who was 27-5 but had been in the sport for a long time without winning a title belt.

“The Last Stylebender” was the strong favorite, and many fans believed he would simply embarrass Strickland with the level of technical ability he possessed as one of the best fighters of his generation.

Strickland responded with one of the most perfect performances UFC fans are ever likely to see. He was calculated, patient, and completely embarrassed the champion on the biggest stage.

Adesanya was never able to find any rhythm, and Strickland walked him down and delivered a catastrophic right hand that nearly ended the fight in the very first round.

That set the tone, and from there Strickland had Adesanya backed up against the cage for most of the fight. By the end of the fifth round, he was charging him, screaming at him, and overwhelmed with his achievement on his way to winning the fight by unanimous decision.

Many people never thought Strickland had a chance, but he showed the world that night.

5. UFC 269: Julianna Pena vs. Amanda Nunes - Co-Main Event

Date: Dec. 11, 2021
Closing UFC Betting Lines: Pena +700, Nunes -1125
Final Result: Pena by Submission (Rear Naked Choke)

Amanda Nunes will go down in history as one of the greatest fighters MMA has ever known. During her prime, she was untouchable, and the UFC was struggling to find challengers that could even pose a threat to her.

Nunes was dominating everyone who dared face her, and she went into her UFC 269 fight against Julianna Pena as more than a -1100 favorite.

Pena nailed her timing throughout the fight, catching Nunes stepping into jab after jab in the second round. Nunes was trying to land a knockout, and seemingly tired, she opened a window for Pena to strike, which is exactly what the challenger did.

The two women stood in the middle of the Octagon swinging, blow for blow. Pena was absorbing the hits and dishing them right back out. She then landed a combination of blows that sent Nunes stumbling backwards.

The challenger seized the opportunity, bringing Nunes to the mat and taking her back before applying a rear naked choke, fulfilling her own pre-fight prediction. It was one of the biggest UFC title upsets in history.

Julianna Pena called her shot as an enormous underdog, and then stepped into the Octagon and pulled it off. Nobody was getting close to Amanda Nunes before that fight, but Pena made it happen.

4. UFC 199: Michael Bisping vs. Luke Rockhold - Main Event

Date: June 4, 2016
Closing UFC Betting Lines: Bisping +450, Rockhold -600
Final Result: Michael Bisping by KO/TKO Punches

Michael Bisping had lost to Luke Rockhold in their first UFC fight in 2014. Two years later, he got a second chance -- this time with a title up for grabs.

Rockhold had beaten Chris Weidman for the title, and the two were set for a rematch at UFC 199. Weidman then had to pull out of the fight with a serious neck injury, leaving the UFC scrambling for a challenger. The 37-year-old Bisping promptly accepted with two weeks' notice, finally getting the title shot he felt he deserved.

He stepped into the Octagon a mere matter of days later to take on Rockhold, who was six years his junior.

Bisping knew he couldn’t go five rounds. He was in good shape but hadn’t had a full camp to prepare for the fight, so he knew he had to come out swinging for the win.

He has commented several times since his victory that he was feeling loose and confident with nothing to lose because nobody expected him to win. The result was one of the best outings of his MMA career. He had wisely prepared to use the left jab to his advantage after having seen a weakness in Rockhold’s defense on film.

It worked perfectly, and he caught the champion off guard with the left. Seconds later, another left dropped Rockhold, and within moments the fight was over.

Bisping was a last-minute stand-in who had been dreaming of such a title fight for his entire life. His ability to show up on just two weeks’ notice and win it was inspirational and made for one of the greatest upsets in UFC history.

3. UFC 193: Holly Holm vs. Ronda Rousey - Main Event

Date: Nov. 14, 2015
Closing UFC Betting Lines: Holm +830, Rousey -1300
Final Result: Holly Holm by KO/TKO Head Kick and Punches

Ronda Rousey had been one of the stars of the UFC, selling out crowds for her fights and taking control as one of the first female champions of the sport. At UFC 193 she ran into Holly Holm in a grudge match, and it was one that her challenger would quickly finish.

Rousey attempted to chase down and attack Holm, but she soon discovered that Holm was adept at fighting defensively. Holm landed powerful strikes each time Rousey advanced, quickly wearing her down.

By the end of the first round, Rousey looked shell-shocked, and Round 2 brought more of the same. Holm was landing at an outrageous rate, while Rousey persisted with an overly aggressive attacking style that ultimately led to her downfall.

This wasn’t just an upset -- it was a complete humiliation. At one point Holm side-stepped an incoming haymaker from Rousey so expertly that it sent the champion to the mat. Just moments later, Holm rocked Rousey right in the mouth with a left, sending her down again.

Rousey quickly jumped back up, turning right into a brutal kick in the face. She went crashing down, and Holm quickly polished her off to steal the title belt in front of a stunned crowd. Perhaps even more stunning was the fact that Rousey never won another fight in the UFC.

2. UFC 173: T.J. Dillashaw vs. Renan Barao - Main Event

Date: May 24, 2014
Closing UFC Betting Lines: Dillashaw +650, Barao -1000
Final Result: Dillashaw by KO/TKO Head Kick and Punches

Renan Barao was starting to look like an unstoppable force in the UFC before he ran into T.J. Dillashaw in 2014. The result of that meeting was one of the biggest upsets in UFC history, since the champion Barao had come into the fight with odds as strong as -1000 to win.

Barao had lost his very first MMA fight back in 2005, but since then had won no less than 31 straight to make him the most impressive bantamweight fighter in the world. His challenger, Dillashaw, had won five of his first six fights in the UFC heading into the title fight against Barao at UFC 173. Despite that, he Brazilian was an overwhelming favorite, and Dillashaw’s fans simply hoped he wouldn’t get too bloodied in the brawl.

The result was something quite different. Dillashaw looked nimble and lightning quick, and after a couple of tidy uppercuts, he landed a sensational overhand right to drop Barao.

After a failed submission, the two got back to their feet, and Dillashaw just kept landing, over and over again. He was switching stances and putting together stunning combinations that the champion simply couldn’t answer.

Eventually, Dillashaw rocked Barao again, and Herb Dean stepped across Dillashaw’s blows as Barao tried to defend himself on the mat. It remains one of the most impressive underdog victories that the UFC has ever seen.

1. UFC 69: Matt Serra vs. Georges St. Pierre - Main Event

Date: April 7, 2007
Closing UFC Betting Lines: Serra +850, St. Pierre -1300
Final Result: Matt Serra by KO/TKO Punches

There is no greater upset in the history of the UFC than Matt Serra’s outstanding first round knockout of Georges St. Pierre at UFC 69 in April 2007.

Many consider St. Pierre the GOAT when it comes to MMA. He was a knockout king and one of the most impressive fighters in the history of the UFC. St. Pierre entered his fight against Serra with a 12-1 record in his MMA career.

Serra had won five of his last six fights, but he was still an enormous underdog against one of the UFCs early superstars. St. Pierre was so fast and dealt so much damage in a variety of ways, making him both unpredictable and extremely dangerous.

Serra was known for the power he possessed, but landing those shots against St. Pierre was a whole different ballgame. However, suddenly, almost in the blink of an eye, Georges “Rush” St. Pierre was out cold on the mat, and Matt Serra was hoisted in the air as the new welterweight champion.

The underdog had remained calm and poised as he landed several blows that damaged St. Pierre. He then landed nearly every shot that followed, buckling the champion until he was flat on his back taking crushing blows to the face that knocked him clean out.

Matt Serra was given zero chance to win that fight, and he not only won it, but did so in astonishing fashion in the very first round against an MMA champion at the peak of his career.

As far as upsets go, you might never see one better.

Parameters of Rankings

These all-time UFC upsets have been ranked based on the shock factor resulting from the underdog’s victory, as well as multiple other factors, including how much time each fighter had to prepare or how long he or she had been competing in UFC before managing to defeat a champion.

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