In 1988 it took all of 91 seconds for him to K.O. Michael Spinks to remain the undisputed heavywight champ
[DOC] [TLE] Mike Tyson Vs Michael Spinks Wbc And Wba Plus Ibf World ... [PAR] Mike Tyson vs Michael Spinks WBC, WBA and IBF World heavyweight title official 
... be recognized as the undisputed heavyweight champion (even though Tyson 
met the ... the lineal champion when he knocked out Michael Spinks after 91 
seconds.