One of the best parts of watching mixed martial arts is the unpredictability. On paper, some matchups appear likely to go one way, but they might play out completely differently.
Here's a look at the five biggest come-from-behind victories in UFC history.
After winning his UFC debut with a record-breaking seven-second knockout of Tim Hague, Todd Duffee had a ton of hype heading into his fight against Mike Russow at UFC 114.
While fans didn't get to witness another quick finish, Duffee controlled the first two rounds, landing several hard shots as the Pride FC veteran displayed an iron chin. However, out of nowhere in the third round, Russow landed a devastating right hand that knocked Duffee out cold.
Russow fought four more times in his career, but his victory over Duffee was by far his most significant bout and remains one of the biggest upsets in MMA history.
For months leading up to their middleweight title fight, Chael Sonnen told the world he was going to dethrone champion Anderson Silva. Fans were thoroughly entertained by his trash talk leading up to the bout. However, few picked the American to upset the 185-pound king.
To the surprise of many, Sonnen dominated Silva with his wresting from the opening bell, landing a number of takedowns and rocking the Brazilian in the first round.
Through the first four rounds, Sonnen was in total control and appeared to be on his way to one of the biggest upsets in UFC history. However, Sonnen's resume included six career submission losses, and he encountered his kryptonite in the final round.
After getting Silva to the mat in the fifth, Sonnen ended up in side control, which ended up backfiring. The champion secured a triangle choke and transitioned to an armbar that forced referee Josh Rosenthal to stop the match.
After losing to Gray Maynard earlier in his career and heading to a draw in their rematch, lightweight champion Frankie Edgar had a lot on the line in his third title defense at UFC 136
Similar to their second encounter, Maynard dominated in the first round, finding a home for his right hand and nearly finishing "The Answer" several times. Somehow, Edgar survived and even managed to pick up some steam, taking the next two rounds.
In the fourth, a much fresher Edgar was able to land a series of combos and kicks, eventually blasting Maynard with two right hands. The Xtreme Couture product got dropped and Edgar took advantage, securing the TKO finish.
Coming off a middleweight title loss to Anderson Silva at UFC 134, Yushin Okami was matched up against Tim Boetsch in something of a bounce-back fight.
That proved to be true through the first two rounds, with the Japanese fighter damaging Boetsch's eye in the early portion of the fight. Okami also nearly submitted the American in the second round. Boetsch survived, but he was down on the scorecards and needed a miracle in the third.
In the final round, "The Barbarian" lived up to his nickname, landing a pair of massive uppercuts that sent Okami to the floor and allowed Boetsch to rain down a barrage of punches. Referee Leon Roberts stopped the match and awarded Boetsch the upset win.
Prior to this matchup, Mirsad Bektic appeared to be the future of the featherweight division with an impressive 11-0 record. But Darren Elkins didn't get the memo.
Though Bektic sliced the Team Alpha Male product open early in the fight, Elkins managed to endure the first two rounds. In the third, Elkins defended a number of takedowns and landed flush with a right hand. "The Damage" followed it up with a kick that dropped the highly touted Bektic for a TKO finish, and Elkins cashed as a nearly 4-1 underdog.