Former WBC heavyweight champion Ken Norton has died at the age of 70.
The Jacksonville fighter, who suffered a heart attack last year, passed away at a care facility in Las Vegas, Nevada on Wednesday.
Norton famously broke Muhammad Ali's jaw on his way to winning the first of a trilogy of fights between them 1973 and 1976.
He was given the world heavyweight title after Leon Spinks opted to fight Ali instead, but he lost the belt in a 15-round battle with Larry Holmes in his next bout.
After retiring with a record of 42-7-1, Norton became a commentator and featured in a number of movies.
Among the first to offer their tributes on Twitter was former undisputed heavyweight champion Lennox Lewis.
R.I.P. Ken Norton - Former World Heavyweight Boxing Champ. Prayers from my family to his. Bless!
— Lennox Lewis (@LennoxLewis) September 19, 2013