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
S. T. Gordon heavyweight bout against future titlist Trevor Berbick before losing his cruiserweight title in 1983 in a rematch with De Leon. He retired after the loss but had a brief comeback in 1987 but was knocked out in the first round by Dwain Bonds. S. T. Gordon ST Gordon (born April 18, 1959 in Pasco, WA) is an American former professional boxer who was the World Boxing Council and Lineal cruiserweight champion of the world in 1982-1983. Gordon became a professional boxer in 1977. He faced undefeated heavyweight prospect Gerry Cooney in 1978 but lost via a fourth-round disqualification. In 1981