Professional boxing knocked him out in brutal fashion. This fight made Hagler famous; he was able to lure Ray Leonard out of retirement in 1987, but lost in a highly-controversial decision. Hagler retired from boxing immediately after that fight. In the latter half of the decade young heavyweight Mike Tyson emerged as a serious contender. Nicknamed "Iron Mike", Tyson won the heavyweight unification series to become world heavyweight champion at the age of 20 and the first undisputed champion in a decade. Tyson soon became the most widely known boxer since Ali due to an aura of unrestrained ferocity, such as that
Heavyweight boxing championship records and statistics At the very beginnings, before the establishment of the sanctioning organizations, the title recognition passed through lineage in the fights under Marquess of Queensberry Rules. The champion was informally called "the man who beat the man". The fight between John L. Sullivan and Dominick McCaffrey is recognized by many boxing historians, including those at The Ring, to be for the inaugural World Heavyweight Championship under the Marquess of Queensberry Rules (however, some dispute that claim for various reasons, including the short distance of the bout, McCaffrey's small size and the fact that both fighters were Americans). The lineage was the