At his peak, as a top-class heavyweight in the late 1960s and early 1970s, Quarry fought Muhammad Ali twice and fought for two versions of the world championship against Jimmy Ellis and Joe Frazier.
He boxed in Britain twice, knocking out the British heavyweight champion Jack Bodell in 64 seconds at Wembley in November 1971, and the following year outpointing his fellow American Larry Middleton.
When he fought Bodell, the notoriously unorthodox Derbyshire southpaw, pre-fight speculation hinged on how long it would take Quarry to solve the style of a man who had just trounced Joe Bugner over 15 rounds. "Did you find him awkward?" said an eager journalist in the dressing room inquest. "Well," said Quarry. "He sure fell awkward . . ." He also twice defeated the British heavyweight Brian London in California, in 1967 and 1969.
After a 200-fight amateur career in California, Quarry turned professional just before his 20th birthday, in 1965. He was unbeaten in his opening 21 contests, and the former heavyweight champion Rocky Marciano went to see his 22nd, at the Olympic Auditorium in Los Angeles, with a view to taking over as his manager. Marciano was disappointed, however, and left before the end as Quarry was outbeaten by Eddie Machen, a veteran contender known as "The Old Professor".
When Muhammad Ali had his boxing licence withdrawn in 1967 for refusing to be drafted into the Vietnam War, the World Boxing Association organised an elimination tournament to decide a new champion. Quarry reached the final, by outpointing Floyd Patterson and then stopping the respected and hard-hitting Thad Spencer in the 12th round. However, he reserved one of his worst performances for the final, a dreary 15-rounder won on points by the negative, counter-punching Jimmy Ellis from Ali's home city of Louisville, Kentucky.
By 1969, Quarry's hard left hooking had brought him back into contention and he was matched with Joe Frazier, who was recognised as champion in New York and several other American states. Quarry was pulled out on the advice of the doctor at the end of round seven. "They never thought I had a heart till that fight," he remembered. "Damned shame I had to show 'em that way."
His most famous night was in Atlanta, Georgia, in October 1970, when he was the "fall-guy" for Ali's comeback from his three- year exile. Quarry was stopped because of a badly cut eye in the third round. It brought him his biggest payday, $338,000.
A rematch with Ali two years later ended in seven rounds, with Quarry admitting afterwards his concentration was deeply affected by a chilling knockout suffered by his younger brother Mike in the previous bout. Mike was knocked unconscious for 10 minutes by the world light-heavyweight champion Bob Foster, and there were, initially at least, serious fears for his health. "I watched it on the monitor in the dressing room and it totally destroyed everything I wanted to do. I thought he had killed my brother."
Quarry enjoyed a revival in 1973 when he outpointed Ron Lyle, a former long-term convict from Denver, and knocked out the thunderous punching Earnie Shavers in one round. He was close to a shot at the winner of the Ali-George Foreman fight in Zaire, but instead fought Frazier again in Madison Square Garden in New York, and was beaten in five rounds. The old champ Joe Louis refereed - and many felt he let it go on too long.
Quarry retired in 1975, following a defeat by Ken Norton, and worked as a bodyguard for the pop group Three Dog Night, returned with a win in 1977 and retired again for six years. The first fears for his health were voiced at this time by Californian doctors, who felt he showed the initial signs of brain damage. After his second fight of 1983, he needed 62 stitches in a gruesome network of cuts, yet he won. "It was fun, but that's enough," he said. The Californian Commission agreed.
He took to selling mobile homes and beer. He once looked back at his tough upbringing and said: "I've led a Grapes of Wrath life . . ." He had been articulate and fresh-faced in his youth, with a passion for poetry, and had said he wanted to move into boxing commentating when he retired from the ring. Instead, he lost the estimated $2.1m he had earned from boxing as his life hit a downward spiral of divorce, drug and alcohol abuse, and a sad refusal to accept that his youth had gone.
"Would I do it all over again?" he said in 1990. "When I started in 1965, I was changing Greyhound Bus tyres for a living, bringing home $99.50 a week. You damned well know I'd go back into boxing. Yes, sir!"
He was surely declining mentally when he fought for the last time, in a six-round club fight in Colorado in 1992, when he could no longer get a licence in California. He absorbed a pounding from a novice named Ron Cranmer. His purse was a fraction above $1,000, but the legacy was terrible.
By 1995 he was in the care of his elder brother James and was officially suffering from severe pugilistic dementia. James set up the Jerry Quarry Foundation, a non-profit charity to assist disabled former boxers who need more help than is provided by the social services. Quarry was frequently confused and had difficulties carrying out simple tasks like shaving or tying shoe laces. "Jerry has 60 per cent short-term memory loss and the temperament of a 12-year-old," said his brother.
Quarry was taken into hospital with pneumonia last week in Templeton, California, and died following a heart attack.
Jerry Quarry, boxer: born 15 May 1945; three times married (three children); died Templeton, California 3 January 1999.