George Louis Chuvalo (born September 12, 1937, as Jure Čuvalo) is a Canadian former professional boxer who was a five-time Canadian heavyweight champion and two-time world heavyweight title challenger. He is known for having never been knocked down in any of his 93 professional bouts including fights against Muhammad Ali, Joe Frazier, and George Foreman. Chuvalo unsuccessfully challenged Muhammad Ali for the heavyweight championship in 1966. Chuvalo was inducted into the Ontario Sports Hall of Fame in 1995. (Via Wikipedia)