Mike Tyson's weight class was heavy.
Heavyweight is a weight class in boxing and other combat sports . Mike Tyson . He reigned as the undisputed world heavyweight champion and holds the record as the youngest boxer to win a heavyweight title at 20 years , 4 months and 22 days old . In 2002 , Tyson fought for the world heavyweight title again at the age of 35 , losing by knockout to Lennox Lewis .