Adonis Stevenson in critical condition after getting KO'd by Oleksandr Gvozdyk

Adonis Stevenson, who lost the light heavyweight world championship by 11th-round knockout to Oleksandr Gvozdyk on Saturday night at the Videotron Centre in Quebec City, was in critical condition at a hospital, promoter Yvon Michel said.

Michel said he and Stevenson's family were with him and that "they want to inform friends and supporters that Adonis is currently in a critical condition in intensive care in the hospital following his fight against Oleksandr Gvozdyk. They appreciate the concern and support of all. There will be no further comments at this time and they respectfully request your understanding in their desire have their privacy."

The precise nature of Stevenson's injury was not announced, but he was transported to the hospital immediately after suffering a brutal knockout in his 10th title defense, a mandatory bout against interim titlist Gvozdyk.

Gvozdyk appeared to be in control for much of the fight -- including scoring a third-round knockdown that referee Michael Griffin simply missed and ruled a slip. But Stevenson, a southpaw, nearly dropped him with a powerful left hand in the 10th round and was ahead on two of the scorecards, a surprisingly wide 98-92 and 96-94, with the third judge having it 95-95 when Gvozdyk unloaded on Stevenson in the 11th round.

Gvozdyk (16-0, 13 KOs) landed eight unanswered punches, including a left hand and two crushing rights that badly hurt Stevenson (29-2-1, 24 KOs), who went down and slumped against one of the corner posts. He tried to get to all fours but fell partially onto the ring apron between the bottom two ropes as referee Michael Griffin waved off the fight at 2 minutes, 49 seconds.

Gvozdyk, 31, a 2012 Ukrainian Olympic bronze medalist who fights out of Oxnard, California, celebrated with his team, including new trainer Teddy Atlas, but when he realized Stevenson was in distress he calmed down. Stevenson, 41, of Montreal, was able to get to his feet and sit down on a stool to be examined by the ringside doctor and appeared alert until his condition deteriorated.

Stevenson, who held the title for 5½ years, was the longest reigning active titleholder in boxing until the defeat.