Looking back at Muhammad Ali's 5 most memorable fights

One of the greatest boxers of all time, Muhammad Ali was a rare athlete who transcended his sport completely, becoming one of the foremost civil rights icons of the 20th century, endearing himself to many by protesting the Vietnam War.

Here we look back at Ali's five best fights from his illustrious career:

Clay vs. Liston, February 1964

Ali still went by his birth name, Cassius Clay, when he took on Sonny Liston in one of the most anticipated clashes in boxing history. Liston entered the bout as the WBA/WBC heavyweight champion, sporting a sparkling 35-1 record, and was viewed as the prohibitive favorite. Clay, advertised as a garrulous talent, provoked Liston relentlessly, calling him a "big ugly bear," and claiming he would "float like a butterfly and sting like a bee."

Clay's speed and agility were evident from the onset, baffling an aggressive Liston, who was seeking an early knockout. Although he took control for the majority of the fight, Clay's eyes were stung by the end of the fourth round, and he asked his trainer, Angelo Dundee, to cut his gloves off. Dundee refused, and Clay recovered to land a number of crushing blows in the sixth round.

While waiting for his opponent to come out for the seventh stanza, Clay noticed Liston couldn't continue, and celebrated a technical knockout - a decision that forever altered the boxing landscape.

Ali vs. Quarry, October 1970

Ali's prime years were wasted as his boxing licence was denied in every state due to his refusal to join the army in the Vietnam War. Eventually, Ali won a licence to fight in Atlanta in August 1970, setting up a bout against Jerry Quarry.

Some prognosticators were skeptical about Ali's form after a three-and-a-half-year hiatus, but "The People's Champion" quickly alleviated all worries in the third round, cutting open Quarry's eye with a clean right-handed blow. Quarry was deemed unable to fight, and Ali won via technical knockout.

Ali vs. Frazier, January 1974

In 1971, Ali lost "The Fight of the Century" to Joe Frazier, and was intent on embarrassing his rival in the rematch. Ali and Frazier engaged in a scuffle two days before the match in an appearance on ABC, further fueling the battle.

Ali engaged in defensive tactics for the vast majority of the fight, throwing jabs and wrapping Frazier along the ropes to minimize the potential for knockout blows. Although Frazier did his best to finish Ali off with brute force, it was all for naught, as the two fighters traded blows in the latter five rounds. Ali's strong start and ability to mitigate major shots led to a unanimous decision.

Ali vs. Foreman, October 1974

Billed as "The Rumble in the Jungle," Ali's first encounter against a previously 40-0 George Foreman is arguably the greatest fight in boxing history. Foreman and Ali both moved to Kinshasa to train in the summer of 1974, setting up the heavily anticipated encounter.

Ali implemented the now-famous "rope-a-dope" strategy for this fight, luring Foreman into throwing massive blows while he deflected the shots along the ropes. While it seemed counterintuitive at first, Ali correctly predicted he could outlast Foreman by getting him to unleash his full arsenal early in the fight.

As the bout continued, Ali took his chance, counter-punching his opponent with a series of crushing blows, while taunting him about his lack of firepower. Ali wore Foreman down in the eighth round, finishing him off with a flurry of punches in the eighth round, recapturing the WBC/WBA championship.

Ali vs. Frazier, October 1975

The final fight of the Ali-Frazier trilogy was dubbed "The Thrilla in Manila," as both athletes looked to gain the upper hand in a contentious series. Ali entered the fight with a 48-2 record, while Frazier was 32-2.

Both fighters fought in 120-degree conditions, which seemed to favor Ali. He aggressively attacked Frazier early, winning the first two rounds before switching back to his "rope-a-dope" tactic with limited success. Frazier took advantage of Ali's mixed tactics, crushing him in the sixth round with a series of powerful blows to the face.

Ali employed the rope-a-dope technique against Frazier, while continuing to throw a flurry of punches that eventually damaged his opponent's eye in the 11th round. Frazier's injured eye continued to worsen as the bout carried on, and Ali hit him so hard in the 13th round that his mouthpiece flew into the audience.

At the end of the 14th round, Frazier's corner decided he inflicted too much damage, and refused to let him re-enter the fight, ending one of the greatest rivalries in sports history.