Heavyweight unification series Heavyweight unification series The heavyweight unification series, also known as the Heavyweight World Series, was a sequence of professional boxing matches held in 1986 and 1987 to crown an undisputed champion of the heavyweight class. The series was produced by HBO Sports and promoted by Don King. It ended with Mike Tyson as undisputed champion, holding the championship belts of the International Boxing Federation, World Boxing Association, and World Boxing Council. Prior to the series, the last undisputed heavyweight champion had been Leon Spinks, who won the championship in his 1978 victory over Muhammad Ali. Spinks had been stripped of
Exhibition fight who held the World Boxing Organization's world Heavyweight title). This fight took place at Youngstown, Ohio. Late in 2014, Chavez Sr. returned to the ring for an exhibition with Vicente Sagrestano in a bout aimed at collecting toys for poor children. He and former rival Mario Martinez, against whom he conquered his first world championship in 1984, faced each other again on July 3, 2015, in an event to benefit Chavez's two drug rehabilitation clinics. Exhibition fight An exhibition fight is a contact sports non-profit event, usually a boxing fight in which participants fight, normally for three rounds. They may