In 1988 it took all of 91 seconds for him to K.O. Michael Spinks to remain the undisputed heavywight champ
[DOC] [TLE] Great rounds of boxing history: Mike Tyson v Michael Spinks, round ... [PAR] Dec 1, 2014 ... Michael Spinks was undefeated in 31 fights when he met Mike ... Tyson ended 
their contest in 91 seconds.