Mike Tyson fought another boxer.
Mike Tyson . He won the WBC title in 1986 after stopping Trevor Berbick in two rounds , and added the WBA and IBF titles after defeating James Smith and Tony Tucker in 1987 . In 1990 , Tyson lost the titles to underdog Buster Douglas , who knocked him out in the tenth round . Attempting to regain the titles , Tyson defeated Donovan Ruddock twice in 1991 , but pulled out of a fight with then-undisputed heavyweight champion Evander Holyfield ( who had defeated Douglas later in 1990 ) due to a rib injury . With his defeat of Bruno , Tyson joined Floyd Patterson , Muhammad Ali , Tim Witherspoon , Evander Holyfield , George Foreman as the only men in boxing history to have regained a heavyweight championship after having lost it . In 2002 , Tyson fought for the world heavyweight title again at the age of 35 , losing by knockout to Lennox Lewis .