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
Floyd Patterson Marciano's announcement, Jim Norris of the International Boxing Club stated that Patterson was one of the six fighters who would take part in an elimination tournament to crown Marciano's successor. "The Ring" then moved Patterson into the heavyweight rankings, at number five. After beating Tommy "Hurricane" Jackson in an elimination fight, Patterson faced former Light Heavyweight Champion Archie Moore on November 30, 1956, for the World Heavyweight Championship. He beat Moore by a knockout in five rounds and became the youngest World Heavyweight Champion in history, at the age of 21 years, 10 months, 3 weeks and 5 days. He