Saul 'Canelo' Alvarez spitefully stopped Billy Joe Saunders to unify the WBC, WBA and WBO super-middleweight titles in Texas.
The Mexican star unloaded a huge uppercut to inflict a nasty swelling around the right eye of Saunders, who did not come out for the ninth round at the AT&T Stadium, Arlington.
After a fiery build-up, Saunders had frustrated Canelo with his slippery southpaw skills, but his spirited resistance was suddenly broken by a four-weight champion who cemented his status as the sport's No 1 fighter.
Stabbing out a swift jab, Saunders searched for his range in the opening round, but Canelo gave a glimpse of his brute force with a thudding body shot.
A straight right forced Saunders onto his heels in the second round as Canelo cranked up his power, prompting roars of delight from his vociferous support.
Saunders shook his head defiantly after withstanding a clubbing right hand in the third, then responded with clusters of precise punches in the fourth.
A left hook ripped through Canelo's guard as Saunders swaggered through the fifth, even sticking his tongue out after landing more sharp counters in the sixth.
Irritation was creeping into Canelo, who was circled by the evasive Saunders in the seventh.
But a huge uppercut staggered the Brit in the eighth and Canelo orchestrated the crowd with his fists before punishing the swollen eye of Saunders.
After that brief, brutal assault, Saunders was unable to continue and his trainer Mark Tibbs waved it off to signal another world title triumph for Canelo.