As the bell went for the end of the 11th round and Paul Ingle staggered back to his corner, the hearts of everyone hunched up against the ringside went out to him. About 15 seconds earlier he had been knocked down and lay on the floor of the ring as the referee counted just short of a knockout.

He looked at the end of his tether, as though he had nothing left to give. To most observers it seemed clear that the world featherweight title fight should have ended there and then.

But over the next minute the decision was taken that he should carry on and try to summon one final burst of energy. It was a decision that could have cost him his life and might still leave him brain-damaged.

This brave, unfashionable fighter, who has won so many bouts seemingly on little more than guts and supreme fitness, was staring defeat in the face and with it the loss of the International Boxing Federation featherweight crown.

Around Sheffield Arena on Saturday night, even Ingle's die-hard fans seemed to know it was a hopeless task. "When he sat down at the end of the round, Steve [Pollard, his trainer] told him he'd lost the fight and Ingle's words were: `I know I've got to stop him in this round'," said Frank Maloney, the boxer's manager. "In that second he seemed clear and was talking perfectly. We had such a short time to make that decision. He responded to everything."

There were gasps of disbelief when Ingle rose unsteadily off his stool to resume combat against the challenger, Mbulelo Botile of South Africa. The round ended 20 seconds later with a left hook. As Ingle sat against the ropes with tears rolling down his cheeks, a British Boxing Board of Control doctor examined the fighter and called in waiting paramedics, who gave Ingle emergency treatment before carrying him away on a stretcher.

Ingle lost consciousness in the ambulance as he was taken to the Northern General hospital in Sheffield, where he was given a scan that revealed a haemorrhage on the right side of his brain. Immediately, he was transferred to the Royal Hallamshire and surgery, which lasted two and a half hours, began only 45 minutes after he was knocked out.

The speed with which Ingle was rushed to the operating table may be crucial to his future quality of life. He is a beneficiary of the change in boxing regulations that came into force after Michael Watson was left brain damaged and partially paralysed after losing a world title fight to Chris Eubank in 1991. Watson had been knocked out in the final round, but crucial minutes were lost before he was taken to hospital. It was around three hours before he received the surgery he needed for a blood clot on the brain, and after weeks in a coma he was left with brain damage and partial paralysis for the rest of his life.

After lengthy consultation with neurological experts, the board of control introduced new regulations which every boxing promoter must follow in staging a show in Britain. As well as a doctor being present at ringside, paramedics and an ambulance must be in attendance, along with an anaesthetist who is qualified to relax a fighter in the event of him suffering critical injury.

All venues are supposed to be within 30 minutes drive of a neurological unit where boxers may be treated in the event of head injuries. All fighters' brains are scanned annually to monitor deterioration and abnormalities. Any fighter who does not match up to standards faces a suspension of his boxing licence.

Medical staff at Sheffield's Royal Hallamshire hospital were yesterday keeping Ingle in a sedated coma, normal practice to allow patients to recover from postoperative trauma in neurological cases, but were optimistic about his chances of making a recovery.

Nevertheless, no matter how well he ultimately regains fitness, Ingle's boxing career is over and his injuries will reopen the debate into whether boxing's safety procedures are rigorous enough.

Promoter Frank Warren, who has been a British licence holder for 20 years, said: "Some men are born to fight and boxing is a sport I love," he said. "You question the parts you play, but you get drawn back in. You try and learn for the future, but it will happen again. Every guy who gets in the ring puts his life on the line."

Dr Jeffrey Cundy, a consultant anaesthetist, said he believed the sport should be banned. "I'm very strongly against it," he said. "What we have seen in the last 10 years is a marked improvement in how to spot signs of bleeding from the brain, but you can have the best doctors around and they won't always be able to help you. Boxers are still dying."