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
Heavyweight boxing championship records and statistics inducted into the armed forces. He was stripped of WBC and WBA titles but remained The Ring and lineal boxing champion, despite not having a boxing match until October 1970. In 2005, Ukrainian boxer Vitali Klitschko retired as WBC Champion. Following his retirement, the WBC conferred "champion emeritus" status on Klitschko, and assured him he would become the mandatory challenger if and when he decided to return. On August 3, 2008 the WBC awarded Klitschko a chance to regain his WBC Heavyweight title against then-champion Samuel Peter. Vitali regained the title after Peter asked the bout be stopped after the