Former U.S. heavyweight boxing champion Ken Norton has died at the age of 70.
His friend and former manager says Norton passed away at a rehabilitation center in Arizona. He was living at the center after suffering a stroke last year.
Norton took up boxing while serving in the U.S. Marine Corps in the 1960s and turned professional after his release from duty in 1967. His victory over boxing legend Muhammad Ali in 1973, during which he broke Ali's jaw, elevated him to the top ranks of heavyweight contenders. He lost a rematch to Ali six months later, then again in 1976 during a bruising title match in Yankee Stadium.
Norton was named the World Boxing Council heavyweight champion in 1977 after Leon Spinks refused to fight him, but he lost the title the next year in an epic 15-round match to Larry Holmes.
Norton retired from boxing in 1981 with a career record of 42 wins, seven losses and one draw.
One of his sons, Ken Norton, Jr., was a star defensive player in the National Football League and now coaches for the Seattle Seahawks.