Mr Watson, now 34, had emergency surgery to remove a blood clot from his brain after the contest with Mr Eubank in 1991. He came to court in London in his wheelchair yesterday to seek compensation from the British Boxing Board of Control.
His case, expected to last six days, is being heard by Mr Justice Ian Kennedy, who is being asked to decide only the issue of liability - not damages - at this stage.
Mr Watson, of Chingford, east London, sitting next to his legal team, listened intently as his counsel, Colin MacKay QC, told the judge of how his career ended and how he had been paralysed down his left side. At the time of the fight he was 26 and at his "peak".
He, Nigel Benn and Mr Eubank "were three British fighters who were at the top of their profession at middleweight", Mr MacKay said.
Mr Watson is suing the board over the events at the end of a World Boxing Organisation super-middleweight contest with Mr Eubank at White Hart Lane, the north London home of Tottenham Hotspur Football Club, in September 1991.
Mr Watson is claiming compensation for his injury and losses, including the ending of his boxing career.
His claim is that the board owed him a "duty of care" to provide medical staff that night with the training and equipment to resuscitate a fighter in his condition. The board is contesting the case.
The court was told that Mr Watson - who is believed to be seeking about pounds 1m in damages if he wins on the issue of liability - had lost about half his brain function. He can stand, shakily, but needs to be supported.
Mr MacKay said: "He will never work again and he will need lifelong care."
His case was that "if he had been in receipt of proper attention in the ring in the minutes that followed his collapse and again during his subsequent transfer to hospital he would not have sustained the brain damage that he now has and as a matter of probability he would have made a complete recovery with the exception that he would never have been a professional boxer again".
He claimed the board owed him a duty of care to provide medical staff in attendance that night with the "training and equipment to resuscitate a fighter in his condition".
Mr MacKay added: "If that had been done he would have arrived in hospital in a condition such that the first-rate neurological attention he then received would have enabled him to quickly recover."
The board's case, Mr Mac-Kay said, was that it owed Mr Watson no legal duty of the kind that was being claimed.
The board would argue that even if he had been given the treatment he said he should have received, he would have suffered the same level of brain damage and disablement.
"They say it would have made no difference to his final outcome," Mr MacKay said. The case continues.Reuse content