Mike Tyson vs. Michael Spinks the sport a month later. The Tyson fight was the only loss of his professional career. Tyson also spoke of retiring, hinting that "this may be my last fight." The win over Spinks has been described as the pinnacle of Tyson's boxing career. It was also his last fight under longtime trainer Kevin Rooney, who was dismissed by Tyson in December. Tyson made two more successful title defences before losing to James 'Buster' Douglas in a major upset in 1990. He continued fighting until 2005, but was unable to replicate his earlier achievements. Tyson and Spinks have both been inducted
Mike Tyson vs. Michael Spinks between Tyson and Spinks grew to settle the issue of who the real champion was, but negotiations were protracted because Tyson's co-managers Bill Cayton and Jimmy Jacobs and Spinks' manager Butch Lewis struggled to agree on terms. Negotiations temporarily broke down when Lewis insisted on a $15 million guarantee for his fighter. Annoyed at constantly being asked about the fight, Tyson eventually demanded that his managers reach an agreement with Lewis. By April an agreement had been reached, although another problem arose when the IBF threatened to strip Tyson of their title if the fight was not scheduled for 15