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
Cruiserweight (boxing) 1980 Camel won and became the first cruiserweight champion. In 1982 the World Boxing Association recognized Ossie Ocasio as their first cruiserweight champion when he defeated South African Robbie Williams (although at that time the WBA called the division "junior heavyweight"). The International Boxing Federation followed suit in 1983 when it matched former WBC champion Marvin Camel against Rick Sekorski for their inaugural title. Camel won and became the first IBF cruiserweight champion. Several boxers moved up to Heavyweight after winning world titles at Cruiserweight. Evander Holyfield unified the WBA, WBC, and IBF titles to become undisputed champion, the first