The Toughest Ali Fought
George Louis Chuvalo, also known as Jure Cuvalo, is a retired Canadian heavyweight boxer who was never knocked off his feet in ninety-three professional fights between 1956 and 1979. He is often considered to have had the greatest chin in the history of boxing and to be one of its most durable fighters ever. He was Canadian heavyweight champion as both an amateur and a professional, and twice fought for versions of the professional world's heavyweight title. He had a long career and fought nearly all the top fighters in the heavyweight division.
Rocky Marciano was one of his trainers in his early career.