Briton Callum Smith's bid to become a two-weight world champion ended in heartbreak after a seventh-round stoppage defeat by the terrific Artur Beterbiev in Quebec.
The Russian systematically broke Smith down to defend his WBC, IBF and WBO light-heavyweight titles.
He floored the challenger twice in the seventh before 33-year-old Smith's corner pulled him from the contest.
"I think it's because of luck," Beterbiev, 38, modestly said.
He maintained his 100% record, having stopped all 20 professional opponents within the distance and is now targeting a unification fight against fellow Russian and WBA champion Dmitry Bivol.
"I need a fourth belt. It would mean in this category I have done my work," said Beterbiev, who hopes to become the first undisputed light-heavyweight champion in the four-belt era.
Liverpool's Smith, the former super-middleweight champion, was stopped for the first time in his professional career, suffering a second defeat in 31 outings.
The challenger made a low-key entrance at the Videotron Centre before Beterbiev, who also holds dual Canadian citizenship, was cheered by the home crowd.
Beterbiev started quickly, unloading within the first 15 seconds but while Smith did settle down, Beterbiev soon took complete control.
Smith was backed up on the ropes midway through the fourth round as straight jabs, hooks to the body and powerful right hands landed cleanly.
The Briton dug in and continued to throw his hands against the undeterred Beterbiev, but the confidence soon appeared to drain from 'El Mundo' Smith, who had been out of the ring since August 2022.
There was little pop to his punches as he was marked up under both eyes, the writing seemingly on the wall.
Two-time Olympian Beterbiev's explosive power is complimented by under-rated boxing skills as he controlled the distance, landing short, sharp sharp and accurate jabs.
A counter right connected with the top of Smith's head midway through the seventh round, and Beterbiev followed it up with a barrage of shots to the head and body.
A helpless Smith crouched down and seconds later slumped to the canvas. He rose to his feet on the count of eight but was floored again seconds later.
Smith's trainer Buddy McGirt entered the ring and signalled to Michael Griffin to call off the contest, and the referee obliged as a deflated Smith sank to his knees, consoled by his brothers.
BBC