Ali's career was filled with highlights and memorable moments, but these are 12 of the ones I'll never forget.
12. Ali shows mercy toward Jimmy Ellis in the 12th round, July 26, 1971 -- Ali faced his friend and former sparring partner, Jimmy Ellis, in his first bout after his famous loss to Joe Frazier. Angelo Dundee, Ali's legendary trainer, trained Ellis for this fight since he was Ellis' manager and trainer and simply served as Ali's trainer. It was a solid performance by Ali, but hardly one of his best. He admitted he wasn't in the greatest shape. But what makes this fight one of Ali's most memorable for me are his actions in the 12th round.
He hit Ellis with a left uppercut that badly hurt him. He then fired off a blazing combination that left Ellis defenseless, sagging against the ropes. Ellis' hands were at his side, but referee Jay Edson didn't immediately jump in to stop it. Ali, though, didn't throw another punch and Edson finally stopped it.
Later, Ali was asked why he didn't simply finish Ellis off.
Asked by a reporter if he didn't throw because Ellis was his friend, Ali indicated that wasn't the reason.
Ali was mean to some of his opponents, particularly those who would refer to him by his birth name, Cassius Clay, rather than as Ali. But he showed class and dignity in the way he dealt with Ellis and it ranks as one of his most memorable ring moments for me.
Cassius Clay hits the deck against Henry Cooper in 1963 (AP)11. Rising from a vicious knockdown to stop Henry Cooper, June 18, 1963 -- Ali would fight Sonny Liston for the heavyweight title in his next fight, and he was a massive favorite to defeat Cooper. But in the fourth round, the course of boxing history was nearly changed.
Cooper cracked Ali with a massive left hook that Cooper's loyal British fans lovingly referred to as 'Enery's 'ammer.' Ali would later joke that he got hit because he was distracted by looking at actress Elizabeth Taylor seated at ringside.
He didn't joke, though, when he spoke of the power of that punch.
But he got up, unsteadily, and survived. Some credit crafty, and perhaps illegal, corner work by Dundee. Ali's glove was torn, and he got an extra minute to get a new one. Dundee also reportedly gave him smelling salts, which would also be illegal.
Ali, then known as Clay, showed his toughness by not only getting up, but by coming out and stopping Cooper in the next round.
10. Knocking out Sonny Liston in the first round of their rematch, May 25, 1965 -- This fight may mark the final time the world heavyweight championship is ever contested in Lewiston, Maine.
Ali won by first-round knockout with what became known as "The Phantom Punch." Some insist Liston took a dive, while others said the punch was so fast that it was hard for the eye to see it land.
The controversy took away from the significance of the win, but it was a big victory for Ali as he was moving ahead in his career.
Clay stopped the great Archie Moore in four rounds in 1962 (AP)9. Stopping the legendary Archie Moore, Nov. 15, 1962 -- Archie Moore is one of the great fighters in boxing history. On this night, he was clearly near the end of the line, and it was a typical boxing match between a wily on-the-way down veteran and a rising young star.
Prior to the fight, many wondered whether Clay, as he was known then, would be able to deal with Moore's experience. Moore had 184 victories, and Clay was just 15-0 entering the bout. Moore had turned professional seven years before Clay was born.
But Clay passed the test, knocking Moore down three times and stopping him in the fourth. After, Moore praised Clay to the Associated Press, telling reporters that Clay was smarter than he'd given him credit for. This was the fight when people began to realize that he would become a serious contender for the heavyweight title.
8. Breaking his jaw in a loss to Ken Norton, March 31, 1973 -- Norton's style gave Ali fits in all three of their matches. Ali won the last two via controversial decisions, but Norton got the decision in this fight, the first time they met. Norton broke Ali's jaw in the second round.
Ali, though, fought on and showed the toughness that would define him, refusing to succumb to the pain.
He proved he was far more than a pretty boy, that he was as tough a fighter as there was in the sport.
Angelo Dundee (L) prepares Ali for his fight with Ernie Terrell (AP)7. Dominated, taunted Ernie Terrell, Feb. 6, 1967 -- Terrell was a highly regarded opponent who had a terrific jab, but Ali dominated, winning 13 of the 15 rounds. He was motivated when Terrell kept referring to him as Clay prior to the fight.
As Ali pummeled Terrell, he would ask him, "What's my name?" He'd then fire off another series of combinations.
This was Ali at close to his greatest. Some would say he was at his physical peak against Cleveland Williams in his fight before, on Nov. 14, 1966, or against Zora Folley, on March 22, 1967. Neither of them were as tough as Terrell, though, and Ali was absolutely brilliant in routing him.
6. Winning the title from Sonny Liston, Feb. 25, 1964 -- Liston was a massive favorite, but Ali cleanly outboxed him and forced Liston to quit on the stool after the sixth round.
After the bout, he changed his name from Cassius Clay to Muhammad Ali. In the ring after the fight, he was screaming, "I shook up the world. I shook up the world. I'm a bad man!"
He proved he was indeed by using his speed and boxing ability to befuddle Liston and stop him in one of boxing's great upsets.
Ali (R) belts Jerry Quarry in 1970 (AP)5. Stopped Jerry Quarry in the third round in first bout after return from exile, Oct. 26, 1970 -- The fight with Quarry was Ali's first after he refused induction into the military and lost his boxing license as a result. He had not fought in three years, seven months and four days when he met Quarry, a quality heavyweight and one of the toughest men in boxing history.
But as tough as he was, Quarry was no match for Ali. Ali was blindingly fast and raked Quarry was hard shots, cutting him open and stopping him in the third round.
4. Losing to Leon Spinks, Feb. 15, 1978 -- This was the beginning of the end of Ali. Spinks, the 1976 Olympic gold medalist at light heavyweight, was 6-0-1 and Ali was a massive favorite.
It was an action-packed fight and was named The Ring's 1978 Fight of the Year, but Ali wasn't in the kind of shape he needed to be in to keep a young, hungry fighter off of him.
Spinks won the final three rounds on all three judges' scorecard to pull out the stunning split decision vicotry.
Ali stands over a fallen George Foreman in 1974 (AP)3. Knocked out George Foreman in Africa, Oct. 30, 1974 -- Foreman was an overwhelming favorite and had been literally destroying the best the heavyweight division had to offer. He won the title in 1973 from Joe Frazier, dropping Frazier six times in less than two full rounds.
Many were concerned about Ali going into the fight. He was losing a lot of his speed and Foreman hit very hard.
But Ali employed the "Rope-A-Dope," tactic, laying back on the ropes to allow Foreman to punch himself out, before turning it on and stunningly stopping him. Some believe it was the greatest victory of Ali's legendary career.
2. Lost to Joe Frazier in 'The Fight of the Century,' March 8, 1971 -- Ask a person 50 years of age or older what happened on March 8, 1971, and odds are pretty good they'll say Ali-Frazier. This fight was not only arguably the most significant in boxing history, it ranks among the greatest sporting events of all-time.
My former colleague, Michael Arkush, wrote an outstanding book about the fight that is well worth reading if you haven't seen it.
But in a battle of unbeaten champions, Frazier used a 15th round knockdown to score a unanimous decision over Ali in an unbelievably good and high-quality fight.
Both men absorbed tremendous amounts of punishment, and Frazier remained in the hospital for days afterward.
Ali (R) battles Joe Frazier in Manila in 1975 (AP)1. Stopped Frazier in 'The Thrilla in Manila,' Oct. 1, 1975 -- Ali made $9 million for this fight, the third in their legendary trilogy, which would work out to about $39 million today. He deserved every penny of that after competing in arguably the greatest fight in boxing history.
After the fight, Frazier said, "Man, I hit him with punches that'd bring down the walls of a city. Lordy, lordy, he's a great champion." Ali was equally impressed by Frazier and said, "I'm going to tell you, that's one hell of a man. God bless him."
Frazier's eyes were swollen shut and he couldn't see when trainer Eddie Futch wouldn't let him go out for the 15th round. There has been talk that Ali wouldn't be able to make it for the 15th and that he got lucky that Futch stopped the fight first, but many in Ali's camp have denied that.
But Ali captured the mood of that fight when he said, "It was like death. Closest thing to dying I know of."
Ali had so many memorable moments, in and out of the ring, in his legendary career, and those are 10 of my picks. Let me know your picks in the comment section below.