In 1988 it took all of 91 seconds for him to K.O. Michael Spinks to remain the undisputed heavywight champ
Michael Spinks to remain the 
undisputed heavyweight champ... [DOC] [TLE] 91 Seconds: Mike Tyson, Michael Spinks and the Knockout that ... [PAR] Jun 27, 2013 ... Michael Spinks' flamboyant manager Butch Lewis, according to a Sports .... from 
the WBC, WBA and IBF, making him the undisputed champion.