Claim: Mike Tyson's weight class was heavy.

Michael Gerard Tyson -LRB- -LSB- ˈtaɪsən -RSB- born June 30 , 1966 -RRB- is an American former professional boxer who competed from 1985 to 2005 . 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 . Tyson won his first 19 professional fights by knockout , 12 of them in the first round . He won the WBC title in 1986 after stopping Trevor Berbick in two rounds , and added the WBA and IBF titles after defeating James Smith and Tony Tucker in 1987 . This made Tyson the first heavyweight boxer to simultaneously hold the WBA , WBC and IBF titles , and the only heavyweight to successively unify them .   Tyson became the lineal champion in 1988 when he knocked out Michael Spinks in 91 seconds of the first round . He successfully defended his titles nine times , which included victories over Larry Holmes and Frank Bruno . In 1990 , Tyson lost the titles to underdog Buster Douglas , who knocked him out in the tenth round . Attempting to regain the titles , Tyson defeated Donovan Ruddock twice in 1991 , but pulled out of a fight with then-undisputed heavyweight champion Evander Holyfield -LRB- who had defeated Douglas later in 1990 -RRB- due to a rib injury .   In 1992 , Tyson was convicted of rape and sentenced to six years in prison , but was released after serving three years . After his release in 1995 , he engaged in a series of comeback fights . He won the WBC and WBA titles in 1996 , after defeating Frank Bruno and Bruce Seldon by knockout . With his defeat of Bruno , Tyson joined Floyd Patterson , Muhammad Ali , Tim Witherspoon , Evander Holyfield , George Foreman as the only men in boxing history to have regained a heavyweight championship after having lost it . After being stripped of the WBC title in the same year , Tyson lost the WBA title to Evander Holyfield by an eleventh-round stoppage . Their infamous 1997 rematch ended when Tyson was disqualified for biting Holyfield 's ears .   In 2002 , Tyson fought for the world heavyweight title again at the age of 35 , losing by knockout to Lennox Lewis . Tyson retired from professional boxing in 2006 , after being knocked out in consecutive matches against Danny Williams and Kevin McBride . Tyson declared bankruptcy in 2003 , despite having received over $ 30 million for several of his fights and $ 300 million during his career . At the time it was reported that he had approximately $ 23 million of debt .   Tyson was well known for his ferocious and intimidating boxing style as well as his controversial behavior inside and outside the ring . Nicknamed `` Iron , '' and `` Kid Dynamite '' in his early career , and later known as `` The Baddest Man on the Planet , '' Tyson is considered one of the best heavyweights of all time . He was ranked No. 16 on The Rings list of 100 greatest punchers of all time , and No. 1 in the ESPN.com list of `` The Hardest Hitters in Heavyweight History . '' Sky Sports rated him as `` the scariest boxer ever , '' and described him as `` perhaps the most ferocious fighter to step into a professional ring . '' He has been inducted into the International Boxing Hall of Fame and the World Boxing Hall of Fame .