Ken Norton, who fought Muhammad Ali three times — breaking his jaw on his way to victory in their first bout, then losing twice — and went on to become the World Boxing Council heavyweight champion, died on Wednesday in Las Vegas. He was 70.

His death was confirmed by his son Ken Norton jnr, an assistant coach with the NFL’s Seattle Seahawks and a professional linebacker for 13 seasons, the Associated Press said. Norton had been in poor health for years after several strokes.

Muhammad Ali, right, winces as Ken Norton hits him during their re-match at the Forum in Inglewood, California. Credit:AP

Norton defeated Ali in a 12-round split decision in 1973 to capture the North American Boxing Federation heavyweight title. Norton was an exceptionally muscular 180 centimetres and 100 kilograms, but an underdog in that first Ali fight.

‘‘Ali thought it would be an easy fight,’’ Norton’s former manager Gene Kilroy was quoted as saying. ‘‘But Norton was unorthodox. Instead of jabbing from above like most fighters, he would put his hand down and jab up at Ali.’’