Undisputed world champion from Aug 1987 to Feb 1990. He won the World Boxing Council heavyweight title 1986 when he beat Trevor Berbick to become the youngest world heavyweight champion. He beat James "Bonecrusher" Smith for the World Boxing Association title 1987 and later that year became the first undisputed champion since 1978 when he beat Tony Tucker for the International Boxing Federation title. He turned professional 1985. Of Tyson's first 25 opponents, 15 were knocked out in the first round. He was undefeated until 1990, when he lost the championship in an upset to James "Buster" Douglas. Tyson was scheduled to fight again for the championship, but was convicted of rape and imprisoned 1992. He was released from prison March 1995.