Briton Daniel Dubois said he felt "cheated out of victory" after his heavyweight world-title challenge ended in defeat by Ukrainian Oleksandr Usyk on a dramatic night in front of 40,000 boisterous fans in Poland.
Dubois, a huge underdog, floored the champion in a controversial fifth round. With Usyk wincing in pain on the canvas, the referee ruled the shot - which appeared to land on the belt line - a low blow.
Usyk, 36, regained control and dropped Dubois, 25, with a flurry of shots in the eighth round at Tarczynski Arena, Wroclaw, before the referee halted the contest following another knockdown in the ninth.
"I didn't think that was a low blow, I thought it landed," Dubois said after the fight.
His promoter Frank Warren agreed, calling it a "complete home decision" as he criticised referee Luis Pabon and said he planned to appeal.
"I like Usyk, but he was not fit to go on and they gave him a couple of minutes to recover," added Warren.
In fact, Usyk took three minutes and 45 seconds before declaring he was fit to resume - fighters are allowed five minutes when caught with a low blow, although Dubois was not deducted a point by the referee.
Usyk, a former undisputed cruiserweight champion, responded well towards the end of the fifth round and reasserted his dominance in rounds seven and eight as he made a successful second defence of his WBA 'Super', IBF and WBO belts.
He also retained his undefeated record, winning a 21st professional bout, to keep hopes of a blockbuster fight with Tyson Fury alive.
"I'm ready to fight Tyson Fury," Usyk said.
"I feel good. I am grateful for my team, my family, my children. I love you. I'm grateful for my country and the Ukrainian army. Thank you so much."
Briton Fury - the WBC world champion - and Usyk have previously failed to agree terms on a historic bout for all four heavyweight belts.
A dramatic, controversial fight
The gulf in boxing fundamentals was clear to see as early as round one with Usyk winning the battle of the jabs.
But Dubois, whose only career loss came against Briton Joe Joyce in 2020, responded by landing an uppercut in the second.
However, Usyk, light on his feet and working at a high intensity, was clearly superior, dancing around the ring, picking Dubois apart in the early rounds.
Lightning lit up the night sky above the open-air stadium in the fifth, seconds later Dubois landed that thunderous right to the body. The crowd gasped, their hero rolling on the floor.
Replays showed the shot was borderline, on the belt. Usyk remained on the floor. He took his time to recover, and had no interest in touching gloves as the contest continued. The dramatic round ended with both men landing punches after the bell.
Usyk then sensed blood as Dubois tired, landing with a flurry of shots in the eighth to floor Dubois.
The challenger bravely got up as the count reached nine, but a straight right in the ninth brought an end to the contest.
Many gave Dubois a puncher's chance heading into the fight, and that may have just been the punch in the fifth round.
"We will order an appeal after what's happened here," Warren said.
"It's all about a legitimate punch that stopped him and he should have won. Everyone wants to see the unification [with Fury, who is in Warren's stable of fighters]. If Daniel had got the result then it would have been easy to do. We will see now."
Rain cannot dampen Ukrainian party
Usyk was fighting in front of a 'home' crowd for the first time since the Russian invasion of Ukraine; a third of those attending had travelled from Ukraine or were refugees now living in Poland or neighbouring countries.
Seven Ukrainian boxers featured on the undercard for the event dedicated to and celebrating a country torn apart through war.
As the rain fell, with the ringside press scrambling for cover, a video message from Ukrainian President Volodymyr Zelenskyy was played on the big screen to a rapturous reception.
Dubois had cut a serious figure throughout fight week, but the challenger made his ring walk grinning and singing along to Bob Marley's 'So Much Things To Say'.
The roaring, ear-splitting noise for Usyk's entrance was something else. He strode to the ring with purpose, not even allowing himself a slight moment to soak in the electric atmosphere.
On an emotionally-charged night, not even the heavy rain could dampen the jubilant Ukrainian fans.
There were wins for British middleweight Hamzah Sheeraz, who beat Dmytro Mytrofanov, and debutant Aadam Hamed - son of boxing legend Prince Naseem Hamed - on the undercard.
But Dubois' hopes of tearing up the script and etching his name into the history books ended in failure, although he will leave Poland with his stock high, while plenty of fans feel he should be a world champion.