Promoter Frank Maloney had to be taken out of Liverpool's Echo Arena on a stretcher by paramedics after watching his prize heavyweight David Price suffer a shock defeat by Tony Thompson.
Maloney, who had a heart attack in 2009 following the death of his fighter Darren Sutherland, was conscious when he left the building but needed treatment by paramedics and was given oxygen after Price was stopped in two rounds by 41-year-old Thompson.
The 60-year-old former manager of Lennox Lewis had attended the post-fight press conference and backed Price to bounce back before falling ill at the venue.
British champion Price was making the biggest step up of his 15-fight career at the Echo Arena having blasted away all of his recent opponents.
American Thompson was viewed as a serious test for the Liverpudlian but Price was expected to pass with flying colours in front of nearly 6,000 fans. However, he started somewhat tentatively and was stunned when a right hook to the ear knocked him senseless and left referee Steve Gray with little option but to stop the fight.
Price said afterwards: "I've been doing that to other people since I turned professional. It's heavyweight boxing. Nobody's invincible. I'll come back from it.
"I didn't take a beating in there tonight it was one of those shots, it caught my ear and my balance had gone. Sometimes it's best to come back as quickly as possible.
"I'm still the British and Commonwealth champion and three fights down the line, this will be ancient history."
Thompson said: "I knew I would do this. It's no shock to me. They thought I was just a name for his record but I showed everyone that I've got a lot left."