Adonis Stevenson retained the WBC light heavyweight title when a badly cut Tavoris Cloud failed to answer the bell for the eighth round in Montreal.
Challenger Cloud suffered a second successive loss as a nasty gash just above his right eye left him unable to continue.
He also had a cut on his left eyelid that he sustained in the opening round of the bout at the Bell Centre after being on the wrong end of a stiff left hand from the champion.
Stevenson thought he had scored a knockdown in the second when the American touched the canvas, only for referee Mike Griffin to rule it as a slip.
Although Cloud did improve he was unable to make much of an impact against the man from Quebec, resulting in 'Superman' taunting him at one stage in the fourth by standing with his arms stretched out, almost offering a free hit.
Towards the end of the seventh a barrage from Stevenson, who is from Quebec and is Canada's only world champion, left Cloud looking a mess.
Once the bell sounded to end the round the decision was quickly taken by the former IBF champion's corner to pull their man out and spare him from taking any further punishment when already so far behind on the judges' scorecards.
"He was covering more so I went to the body," Stevenson said afterwards. "Sometimes I went for the head and sometimes the body. It worked out well.
"You see after seven rounds I could still box him. My trainer did a very good job. In four months I have beaten two great champions at the weight."
Next up for the Haitian-born southpaw will be a mandatory defence against no 1 challenger Tony Bellew, with the British fighter having watched on at ringside on Saturday night.
"So Stevenson won! I'll be back here soon enough though and believe me when I come back here I'm taking his belts home with me!" Bellew wrote on Twitter afterwards.
Meanwhile, on the undercard, former champion Jean Pascal stopped George Blades in the fifth round of their light-heavyweight fight.
Pascal (28-2-1) recorded with three knockdowns as he used the outing as preparation for his scheduled clash with fellow Montreal fighter Lucian Bute at the start of next year.