Saul Canelo Alvarez stopped Billy Joe Saunders after the eighth round of their huge super middleweight title fight in Texas.
A powerful uppercut from the Mexican (56-1, 38 KOs) caused Saunders' swollen eye to close badly and his corner decided he was in no position to continue when receiving treatment ahead of the ninth round. He was subsequently taken to hospital with a suspected broken orbital bone.
The judges were scoring the fight 78-74, 77-75 and 78-74 in Canelo's favour at the time but many pundits and fellow boxers felt it was a lot closer than that as the previous unbeaten British star (30-1, 14 KOs) gave an impressive account of himself against a true legend of the sport.
Canelo now adds the WBO belt to his collection that already included the WBC, WBA and Ring Magazine titles and is now targeting Caleb Plant's IBF crowd to become the undisputed champion.
More than 73,000 people were in attendance for the highly-anticipated fight, which began with Saunders exploding out of the blocks with a ton of energy, but failing to land a scoring shot.
After Saunders’s early burst, Alvarez took control of the ring to trap the Englishman in the corner and sneak in multiple shots to the body.
Alvarez maintained the advantage throughout the early rounds, but was unable to deliver a killer blow.
The momentum briefly switched in the fifth round when Saunders stunned the Mexican with a strong left hook.
However, Alvarez quickly regained his composure, outworking his opponent until he landed a flurry of head punches in the eighth round which opened up a cut below Saunders’s right eye that effectively sealed his victory.
Canelo said: "The plan is to go for all the belts. I'm coming for Caleb Plant!"