Undisputed champion he was still described as "undisputed champion" by some reports. After Joe Calzaghe's super middleweight victory over Mikkel Kessler in November 2007, he was frequently described as "undisputed champion". Others disputed this, because although he held the WBA, WBC, and WBO belts, he vacated his IBF title in November 2006 rather than face a mandatory challenger, and immediately vacated other titles as well. The unified champion is defined as a boxer that holds at least two world championships of major sanctioning bodies (WBA, WBC, WBO or IBF) in their respective division. Around 2004, the World Boxing Association recognized three different
Undisputed championship Olympic Auditorium World Heavyweight Championship. In light of having unified three of the major world heavyweight championships of his time (as well as numerous other lesser-prestige titles) and defeating the reigning AWA World Heavyweight Champion in a non-title match (a major title that was abandoned soon after), Thesz became the Undisputed Champion for some time. From that point onward, the National Wrestling Alliance World Heavyweight Championship (the championship belt that Thesz opted to keep as the designation of all the championships he had won) became the undisputed world heavyweight title for all contenders to seek. This, however, would change over