One could argue that the sport of MMA is the easiest one to see an underdog burst through the ceiling of limitation and find success. At every level of the sport, it takes one mistake standing up or on the ground for anyone to find a victory.
Over the history of the sport, there are countless times that fans have either had their dreams crushed or even sometimes their bank accounts. Imagine you place a nice bet on the recently retired Shogun Rua when he came to the UFC. You see he is matched up with Forrest Griffin and you can’t load enough money into your Match.Center account so you can bet this, all for it go the way of the underdog in Griffin.
That is just one example of the beauty of the sport of MMA, what Griffin did from there got him into the UFC hall of fame and helped him win a title. While that won’t be remembered as one of the biggest upsets in the sport’s history, there are plenty of others to choose from.
Ronda Rousey (-2000) vs. Holly Holm at UFC 193
Heading into UFC 193, no one was riding a bigger wave of momentum and dominance than Ronda Rousey. Her matchup against Holly Holm was seen as another example of a lamb being led to slaughter due to her background in boxing to Rousey’s judo. Despite being a massive favorite, Holm was able to shock the world and seemingly send Rousey into orbit.
Rousey would never be the same and would only compete one more time in the UFC before retiring. In the case of Holm, she wouldn’t defend the title successfully as she would lose it to longtime Rousey rival Meisha Tate just five months later. Regardless of how their paths went after UFC 193, no one can argue that this was one of the biggest upsets in MMA history.
Georges St-Pierre (-1300) vs. Matt Serra at UFC 69
The upset that arguably led to Georges St-Pierre becoming the legend he is now seen as. St-Pierre was riding a six-fight win streak and was coming off a title win over rival Matt Hughes as he avenged a previous loss. Whether it was lightning striking or St-Pierre not preparing, Matt Serra took advantage after winning the fourth season of the Ultimate Fighter.
He rocked St- Pierre in round one, rushed him and forced the Canadian champion to tap to strikes. The ultimate win for an Ultimate Fighter in Serra, while he didn’t have the career that St-Pierre did, he has left a lasting legacy on the sport with his performance.
Amanda Nunes (-1100) vs. Juliana Pena at UFC 269
The biggest upset in recent memory of MMA fans would undoubtedly be Amanda Nunes losing to Juliana Pena. Nunes has cemented herself as the greatest female fighter of all time, one of the best in general, and Pena was seen as another feather in her cap. Instead, another former Ultimate Fighter winner in Pena scored the upset by outmatching the legend.
Pena caught the champion early and never allowed her to recover and won the title she had been pursuing her whole career. While Nunes would win the title back in a rematch, the upset of an 11-1 favorite will never not be shocking to fans and media alike.
Renan Barao (-900) vs. T.J. Dillashaw at UFC 173
The week of UFC 173, UFC President Dana White famously dubbed Renan Barao as the pound-for-pound king of the sport. He did so for good reason as the Brazilian champ was riding a 31-fight winning streak and was coming off his best performance to date against Urijah Faber.
The storyline revolved around Faber’s protege T.J. Dillashaw getting a chance at revenge for his teacher. Dillashaw had never come across as a clinical striker but no one could argue otherwise after his performance. Dillashaw made Barao look like an amateur at times and would win their rematch and secure himself a legacy that is both great and complicated. It all started with one performance and sometimes that is all it takes, despite what the odds will tell you.
Joanna Jedrzejczyk(-550) vs. Rose Namajunas at UFC 217
Rounding some of the more memorable and biggest upsets in MMA history, you have to include Rose Namajunas catching and knocking down the strawweight queen Joanna Jedrzejczyk. Leading up to UFC 217, the Polish champion had attempted to mentally break her opponent but Namajunas proved none of that mattered.
What would come as a result is the famous call by Daniel Cormier of “Thug Rose! Thug Rose!” as Namajunas secured a knockout victory. Namajunas has seen ups and downs but remains a focal point of the division and a fan favorite as a result of her legendary performance.