Forty years ago, on October 30 1974, one of the most epic events in sporting history took place in Kinshasa, Zaire (now the Democratic Republic of Congo), when Muhammad Ali and George Foreman met in the ring for a fight that will forever be immortalised as The Rumble in the Jungle.

It was a fight that saw an ageing 32-year-old Ali risk not only his legacy but his health against the human wrecking machine that was a 25-year-old George Foreman in his prime.

Foreman was the undefeated reigning heavyweight champion, and prior to meeting Ali had destroyed both Ken Norton and Joe Frazier inside two rounds, each of whom had already defeated Ali.

Standing 6'3" and weighing in at a lean 220lbs, Foreman brought to the ring punching power that was considered by many to be the most terrifying of any heavyweight there had ever been. Hardly anybody in the sport gave Ali a prayer going into the fight, including members of his own camp.

The build-up was almost as dramatic as the fight itself, captured for posterity in the superb documentary When We Were Kings. Pulling the strings was promoter Don King — then at the beginning of what was destined to be a long and controversial career as the dominant force in the sport.

The way King managed to put the fight together is worthy of being studied at Harvard Business School, if only for the way it strips bare the veneer of respectability surrounding the world of business to expose the lying, cheating and scamming which lies at its heart.

Each fighter was to be paid a purse of $5 million — $24m today — which was unprecedented at that time. The only problem was that King didn’t have a penny to his name. He managed to get British movie producer John Daly to come up with an initial $1.5m down-payment in order to get both fighters’ names on the contracts, before he set about hustling to raise the rest. After trying various options, King approached Joseph Mobutu — the president and brutal dictator of the former Belgian colony of Zaire. King was able to convince Mobutu that hosting the fight would promote his country and show him in a positive light across the world. Mobutu was swayed and duly came up with the rest of the money.

Both fighters spent most of that summer in Zaire preparing for the fight. Originally scheduled to take place in September, it had to be put back to October when Foreman sustained a cut in sparring. No matter, Ali used the time to great effect, cementing his bond with the African people who worshipped him. Every time he appeared in public they would chant: “Ali, bomaye!” — “Ali, kill him!”

Foreman had none of Ali’s charisma or personality. When he wasn’t training he preferred to remain secluded in his hotel surrounded by his entourage. Ali never lost an opportunity to play mind games with his opponent, taunting him mercilessly in his trademark style at press conferences and other public appearance. He assured the world that Foreman was too slow and ponderous to beat him. Naming him “The Mummy,” he would impersonate his style in the context of a pantomime mummy — slow, mechanical and stiff.

But Foreman’s size and strength belied a fighter who possessed neat footwork.

Anticipating that Ali would spend much of the fight making him chase him, Foreman worked in training on cutting off the ring against much smaller and faster sparring partners.

The reigning world champion’s strategy going into the fight was as simple as it was brutal — cut the ring off and bludgeon Ali into submission in the first few rounds and end the fight quickly, just as he had against Norton and Frazier.Despite promising that he would dance like the fighter of old, Ali’s legs were nowhere near the same as they’d been prior to his enforced absence from the ring as a result of his stance on the war in Vietnam. But Ali was not a legend of the sport for nothing. Rather than dazzle and dance like the younger version, the older version relied on an inordinate ability to find a way to win whatever it took.

This is exactly what he did in Zaire.

In the first round Ali surprised his younger and bigger opponent with a series of lightning-fast right-hand leads, beating Foreman to the punch time and again. Foreman went berserk and began stalking Ali round the ring, intent on knocking him out. Ali danced and moved as he said he would. But, as he later admitted, by the end of the first round he realised that he wouldn’t be able to keep it up. This is when the world was introduced to the famed “rope a dope.”

The thousands of spectators watching in the stadium, the phalanx of writers and journalists watching ringside, the millions watching live around the world live via telecast and last but not least Ali’s own corner — none could believe what they were seeing. Ali had allowed himself to be trapped on the ropes and was inviting Foreman to tee off on him with his best shots.

It seemed suicide, especially against one of the hardest-punching heavyweights the sport had seen. But round after round Ali continued to remain on the ropes absorbing Foreman’s punches, leaning back over the ropes to avoid the most dangerous head-shots, all the while taunting his opponent with his inability to register the KO he and his camp had fully expected. The punches that did get through would have been enough to stop lesser fighters. But Ali’s levity and huge personality outside the ring concealed a man who had steel in his veins and the heart of a lion.

By the start of the eighth round the method in Ali’s madness became clear. Foreman had punched himself to the point of exhaustion, until he could hardly lift his arms as he continued with his tactic of delivering bombs. Ali continued to talk to and goad him, getting Foreman to punch harder and tire himself out more and more.

Halfway through the round, sensing that his opponent was out on his feet, Ali suddenly exploded off the ropes and with a sensational five-punch combination forced George Foreman down onto the canvas for the first time in his career. Drunk with exhaustion, Foreman had nothing left and he was counted out before he could get back to his feet.

The crowd erupted. Ali had triumphed against the odds, regaining the title that had been stripped from him because of his opposition to the war in Vietnam and proving to the world that, in the words of Norman Mailer, genius really is the ability to “balance on the edge of the impossible.”

As Ali said immediately after the fight while being interviewed in his dressing room, pointing to the camera as he addressed the boxing writers and pundits who’d predicted his defeat: “All you suckers bow! I am the greatest!”

He truly was.