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
World Heavyweight Championship (WWE) and championships among other assets. The slew of former WCW talent joining the WWF roster began "The Invasion" which effectively phased out the WCW name. Following this, the WCW World Heavyweight Championship was unified with the WWF Championship, the WWF's world title, at Vengeance in December. At the event, the WCW World Heavyweight Championship was decommissioned with Chris Jericho becoming the final WCW World Heavyweight Champion and the subsequent Undisputed WWF Champion after defeating The Rock and Steve Austin respectively. The WWF title became the undisputed championship in professional wrestling until September 2002 with the creation of the World Heavyweight