Tyson is a former undisputed heavyweight champion of the world and holds the record as the youngest boxer to win the WBC, WBA and IBF heavyweight titles at 20 years, 4 months, and 22 days old. Tyson won his first 19 professional bouts by knockout, 12 of them in the first round. He won the WBC title in 1986 after defeating Trevor Berbick by a TKO in the second round. In 1987, Tyson added the WBA and IBF titles after defeating James Smith and Tony Tucker. He was the first heavyweight boxer to simultaneously hold the WBA, WBC and IBF titles, and the only heavyweight to successively unify them. In 1988, Tyson became the lineal champion when he knocked out Michael Spinks after 91 seconds. Tyson successfully defended the world heavyweight championship nine times, including victories over Larry Holmes and Frank Bruno. Tyson is considered one of the best heavyweights of all time. He was ranked No. 16 on The Ring's list of 100 greatest punchers of all time and No. 1 in the ESPN.com list of "The hardest hitters in heavyweight history". He has been inducted into the International Boxing Hall of Fame and the World Boxing Hall of Fame.