Artur Beterbiev came out on top of a firefight with Britain's Anthony Yarde to retain his WBO, WBC and IBF light-heavyweight world titles in London.
Both men fought brilliantly in a back-and-forth epic over eight rounds.
Yarde hurt Beterbiev in an astonishing fifth round, but was then pulled out of the fight in the eighth after being knocked down by a powerful right hand.
Russian Beterbiev kept his 100% knockout record, while Yarde's wait for world honours goes on.
"I could say it was a bad fight but I'm sitting here," Beterbiev told BT Sport.
"Everyone in this division can punch and Anthony can too. He's young and he has time and I hope he does well in the future.
"If I'm honest, I was prepared for all of those punches and that's why I could keep coming back at him."
Yarde was a huge underdog going into the contest, but will see his stock rise rapidly after an impressive performance many might have thought beyond him.
A potential win for the 31-year-old Londoner was being likened to some of the biggest upsets on British soil but the stage was certainly set for a classic as Yarde, dressed in white shorts with gold trim, was given a hero's welcome by the OVO Arena in Wembley.
Despite being the defending champion, Beterbiev made a lightning-quick entrance and was booed heavily as he did.
The first round was skittish for long stretches with Yarde clearly wary of the 38-year-old Russian's renowned power which had yielded 18 knockouts from 18 fights.
But it was the Briton who landed first with a lovely counter left hook which pushed Beterbiev backwards.
"Fight this guy" was the shout from Beterbiev's corner and the unified champion tried to oblige, surging forward whenever he could.
Beterbiev, who holds a Canadian passport, is now unbeaten in 19 fights
Beterbiev's face was reddened in the second thanks to Yarde's excellent countering and when the Russian landed a sweet right hand, his opponent immediately responded with another left hook.
Yarde was then forced to fight his way out of the corner after Beterbiev did magnificently to close the distance, a feat he achieved throughout the fight.
The crowd, however, were firmly on Yarde's side and every one of his shots drew a huge roar.
A strong uppercut from Yarde caught the eye, but Beterbiev continued to step forward, undeterred.
There was no rest for Yarde and he was stunned several times in the fourth round as Beterbiev stepped up the pace.
A firefight then broke out in the fifth as Yarde landed a massive right hand flush on Beterbiev.
The crowd were on their feet baying for a finish with Beterbiev clearly hurt but the Russian threw himself into the arms of Yarde to gain a few vital seconds of recovery.
Yarde poured forward in a bid to end the fight but Beterbiev fought back in kind and unleashed a flurry of punches, leaving his rival swaying on his feet as the bell arrived.
There was now blood coming from the left eye of Beterbiev while Yarde's was swelling with each passing second.
Yarde tried to replicate the shot that had wobbled Beterbiev by going over the champion's jab in the sixth, but this time his opponent was wise to the attack.
Beterbiev v Yarde
Both fighters unleashed brutal punches in a sensational contest
The seventh round produced more stunning action as once again Yarde stepped forward and seemingly hurt Beterbiev.
But Beterbiev circled away from danger and masterfully turned the British fighter to trap him in the corner, where he then unloaded and a dazed Yarde could only stand his ground.
Yarde appeared on the verge of going down, but stayed on his feet and eventually was able to escape and see out the round.
The eighth round saw the final shots of an incredible fight. A tiring Yarde reached for a left uppercut, but Beterbiev read it beautifully and landed a strong right hand.
Another followed to floor Yarde and, while the challenger was able to get up, he looked back at his corner, clearly in two minds about whether to continue.
The referee allowed the fight to continue but Yarde's coach Tunde Ajayi quickly made the decision to wave the white flag as Beterbiev bared down on his fighter.
BDST: 1222 HRS, JAN 29, 2023