Martin Power lost his chance of landing the vacant Commonwealth bantamweight title when he was stopped by South Africa's Tshifhiwa Munyai in London.
The British champion, 26, suffered his first professional loss when referee Victor Loughlin ended the contest one minute and 35 seconds into round nine.
Two judges had the Londoner ahead when the fight was halted, leaving Power and his corner fuming at the decision.
Power said: "I didn't think it should have been stopped. I was still in it."
Power had been set to face old adversary Ian Napa for a defence of his domestic crown, but his fellow Briton had pulled out with injury.
Instead, Munyai, who has only fought in four and six rounders in his career, stepped in for the York Hall clash.
Power, despite a typically gutsy display, admitted he found the stand-in an extremely tricky opponent.
It's disappointing as you are in the fight until the final bell... it only takes one punch and it could have been over
"The kid was very tall and game," he said. "I should have kept my hands up a bit more and used better combinations to fend him off, but he was strong.
"It's disappointing as you are in the fight until the final bell and it only takes one punch and it could have been over.
"I'd love a rematch but he will be hard to beat."
Munyai, who had only fought in 10 professional bouts before this encounter, showed he has a real future.
His stinging jabs and lightning left and right combinations made it a tough night for the Briton, who looked slightly unsettled by his opponent's range of skills.
Munyai said: "I wanted to stop it early. The referee made his own decision about stopping the fight and he's done his job but I'd love to come back and defend my title here."
Promoter Frank Maloney admitted that his concern for his fighter may have resulted in the bout being ended early.
"Watching from ringside I thought Martin was in touble," Maloney said.
"I looked at his trainer and maybe the referee saw me and thought I was going to pull him out.
"It's one of those things but hopeflully we can get a rematch for Martin."