Sporting great and global icon Muhammad Ali died four years ago on June 3.

Here we take a look back at some of the most memorable moments of the boxing legend's career.

CLAY-LISTON I

Ali – then known as Cassius Clay – went into his first clash with Sonny Liston as the huge underdog, with the defending WBA and WBC heavyweight champion having picked up two emphatic first-round victories over Floyd Patterson. However, Liston failed to emerge from his corner for the beginning of the seventh round, handing Ali victory. The bout, as well as the re-match won by Ali, was dogged by allegations of fixing, although the claims were never substantiated.

THE FIGHT OF THE CENTURY

Ali had won 31 fights on the bounce by the time he came to face Joe Frazier for the first time in 1971. Ali, having been stripped of his titles and served a three-and-a-half-year ban for rejecting military service, was looking to win back the titles he had been forced to vacate prior to his suspension. However, it was Frazier who eventually emerged as victor by unanimous decision, dropping Ali with a crunching left hook in the 15th and final.

RUMBLE IN THE JUNGLE

Victory over Frazier in a non-title rematch was the ideal morale-booster for Ali ahead of a showdown with feared champion George Foreman in Zaire (now Democratic Republic of Congo). Foreman had beaten Frazier in 1973 and successfully defended his belts in subsequent fights against Jose Roman and the Ali-conquering Ken Norton, heading to Africa as favourite. However, Ali employed what became known as his rope-a-dope tactic of leaning on the ropes, allowing Foreman to punch himself out and directing straight punches at his opponent's face. The approach worked, as Ali stopped an exhausted Foreman in the eighth.

THRILLER IN MANILA

The third and final bout between Ali and Frazier lived up to and beyond the promise of the earlier two, delivering a brutal and at times horrifying classic for the ages. Frazier's team spent the build-up warning against the underhand tactics they felt Ali used to emerge victorious in their second meeting. However, it was the champion who eventually came out on top, battered but victorious after 14 savage rounds.

THREE-TIME CHAMPION

There remains a strong argument that Ali should have disappeared off into the sunset after that final Frazier epic, but on he went. By the time he lost his crown to Leon Spinks – the 1976 light-heavyweight Olympic champion but a seven-fight novice as a professional – he was a shadow of his former self. Nevertheless, Ali retained enough wily ring smarts to win their 1978 rematch in New Orleans, becoming the first fighter in history to reign as heavyweight champion three times.