While still fighting, Foster also worked as a deputy in the Bernalillo County Sheriff’s Department and even ended up presenting his gallant British opponent with an honorary deputy’s badge.

Born in Borger, Texas, on December 15 1938, Foster moved with his family to Albuquerque as a small child and attended Albuquerque High before joining the United States Air Force.

Having failed to represent the United States at the Olympics, Foster launched his professional career in Washington DC in March 1961, but returned to his home town after defeating the hard-hitting Tiger.

Their clash – at New York’s Madison Square Garden on May 24 1968 – saw Foster announce his arrival on the world stage by knocking out the veteran Nigerian for the first and only time in Tiger’s 81-bout career.

A tall, lean and rangy 6ft 3ins, Foster had a physique that enabled him to gain tremendous leverage with his punches. “He even hurts you with a left jab,” a rueful Finnegan explained. “It’s like being hit in the face with a scaffolding pole with a boxing glove on the end of it.”

These attributes were not enough when Foster rashly decided to move up to heavyweight to challenge the unbeaten Frazier for the WBA and WBC crowns, however – a contest which saw Foster concede 21 lbs to his stocky opponent who was then approaching the prime of his career.

Foster had made 11 successful light-heavyweight title defences at the time of his first ill-fated assault on the world heavyweight crown at Detroit on November 18 1970. Having managed to keep the champion largely at bay with his spearing left jab in the opening round, Foster was floored heavily by a short left hook early in the second before a similar punch left him prone on the canvas in the second. The contest was rightly regarded as a mismatch and a chastened Foster duly returned to the 175lb division where he remained dominant.

Yet some of Foster’s own knockout victories rank among the most spectacular ever seen. His stoppages of Tiger, Vicente Rondon and the previously undefeated Mike Quarry were among the most dramatic, Foster later revealing that the latter destruction of the younger brother of heavyweight title contender Jerry Quarry had left him shaken.

“When I hit Mike Quarry, I thought he was dead,” he recalled.

Apart from Finnegan, Foster’s toughest light-heavyweight opponent was the South African Pierre Fourie, who twice took him the distance.

Foster initially held his own against Ali when the pair clashed for the North American Boxing Federation title in Nevada on November 21 1972. All that changed in the fifth when a seemingly enraged Ali found another gear having suffered a rare cut. Foster, who unwisely opted to go toe-to-toe with his bigger opponent, was floored four times and only his fighting heart kept him in the contest until the eighth.

Foster announced his retirement in 1974, although like so many fighters before and since, he could not stay away from the sport. Despite clearly being overweight he returned the following year to launch a string of victories against mediocre opposition.

Finally, a stoppage defeat against former victim Bob Hazelton on June 2 1978 persuaded Foster to hang up the gloves for good. He finished with a professional record of 56 wins, eight losses and one draw with 46 knockouts – all of his defeats coming against heavyweight opposition.

Foster, who was married four times, retained his link with the sport as a trainer, and among the young fighters he mentored was his own son, Tony, who matured into the heavyweight his father had never quite managed to be.

Foster accompanied his former opponents Ali, Frazier and Tiger in the International Boxing Hall of Fame in 1990.