Anthony Ogogo has confirmed he twice dislocated his shoulder while beating Ukrainian Ruslan Schelev in his latest professional fight.
The 26-year-old Lowestoft-based middleweight out-pointed Schelev in Halle, Germany on Saturday.
Ogogo, who won a bronze medal at London 2012, told BBC Suffolk he had to "wiggle" the joint back into place.
"It took a lot of guts. The plus side is I beat the best guy I've faced so far with one arm," he said.
Ogogo, who is managed by 10-time champion Oscar De La Hoya, has won all eight fights since turning professional two years ago, but has also suffered a number of injury problems.
He has twice undergone surgery to relieve pain in both his Achilles tendons and also needed surgery after a previous shoulder dislocation.
"I got the win, that's the most important thing, but it was bitter-sweet because in the second round I dislocated my right shoulder," he said.
"I had to kind of wiggle to get the shoulder back in its socket, I was in a serious lot of pain.
"I tried to use it again in the third round, the same thing happened, so I had to navigate the rest of the bout with one arm."
Ogogo said he will now have a scan on the shoulder but plans to be back fighting before the end of the year.
"I'm not too down, I fought a good fight against a very good opponent and beat him with one arm, and I'm confident I'll beat this injury," he added.
"It's unlucky and frustrating, but I've gone 39 rounds as a professional boxer now and won every single one and I'll be back in no time at all."