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
World Heavyweight Championship (Zero1) World Heavyweight Championship (Zero1) The World Heavyweight Championship is a professional wrestling world heavyweight championship in the Japanese promotion Pro Wrestling Zero1. It is one of Zero1's top two singles titles, along with the NWA United National Heavyweight Championship. It was first introduced on December 15, 2007 when Zero1 ended their relationship with the AWA Superstars of Wrestling. The Superstars of Wrestling champion at the time, Masato Tanaka, was then recognized as the first Zero1 World Heavyweight Champion. To this day, Zero1 continues to use the AWA title belt, which reads "AWA World Heavyweight Wrestling Champion", to represent the World