From 1960 to 1963, the young fighter amassed a record of 19–0, with 15 knockouts. He defeated boxers such as Tony Esperti, Jim Robinson, Donnie Fleeman, Alonzo Johnson, George Logan, Willi Besmanoff, Lamar Clark (who had won his previous 40 bouts by knockout), Doug Jones and Henry Cooper.
Clay built a reputation by correctly predicting the round in which he would "finish" several opponents, and by boasting before his triumphs. Clay admitted he adopted the latter practice from "Gorgeous" George Wagner, a popular professional wrestling champion in the Los Angeles area who drew thousands of fans. Often referred to as "the man you loved to hate," George could incite the crowd with a few heated remarks, and Ali followed suit.
Among Clay's victims were Sonny Banks (who knocked him down during the bout), Alejandro Lavorante, and the aged Archie Moore (a boxing legend who had fought over 200 previous fights, and who had been Clay's trainer prior to Angelo Dundee). Clay had considered continuing using Moore as a trainer following the bout, but Moore had insisted that the cocky "Louisville Lip" perform training camp chores such as sweeping and dishwashing. He also considered having his idol, Sugar Ray Robinson, as a manager, but instead hired Dundee.
Clay first met Dundee when the latter was in Louisville with light heavyweight champ Willie Pastrano. The teenaged Golden Gloves winner traveled downtown to the fighter's hotel, called Dundee from the house phone, and was asked up to their room. He took advantage of the opportunity to query Dundee (who was working with, or had, champions Sugar Ramos and Carmen Basilio) about what his fighters ate, how long they slept, how much roadwork (jogging) they did, and how long they sparred.
Following his bout with Moore, Clay won a disputed 10-round decision over Doug Jones in a matchup that was named "Fight of the Year" for 1963. Clay's next fight was against Henry Cooper, who knocked Clay down with a left hook near the end of the fourth round. The fight was stopped in the fifth due to deep cuts over Cooper's eyes.
Despite these close calls, Clay became the top contender for Sonny Liston's title. Despite his impressive record, however, he was not widely expected to defeat the champ. The fight was scheduled for February 25, 1964 in Miami, Florida, but was nearly canceled when the promoter, Bill Faversham, heard that Clay had been seen around Miami and in other cities with the controversial Malcolm X. At the time, The Nation of Islam—of which Malcolm X was a member—was labeled as a hate group by most of the media. Because of this, news of this association was perceived as a potential gate-killer to a bout where, given Liston's overwhelming status as the favorite to win (7–1 odds), had Clay's colorful persona and nonstop braggadocio as its sole appeal.
Faversham confronted Clay about his association with Malcolm X (who, at the time, was actually under suspension by the Nation as a result of controversial comments made in the wake of President Kennedy's assassination). While stopping short of admitting he was a member of the Nation, Clay protested the suggested cancellation of the fight. As a compromise, Faversham asked the fighter to delay his announcement about his conversion to Islam until after the fight. The incident is described in the 1975 book The Greatest: My Own Story by Ali (with Richard Durham).
During the weigh-in on the day before the bout, the ever-boastful Clay, who frequently taunted Liston during the buildup by dubbing him "the big ugly bear" (among other things), declared that he would "float like a butterfly and sting like a bee," and, summarizing his strategy for avoiding Liston's assaults, said, "Your hands can't hit what your eyes can't see."
First title fight and aftermath
Main article: Muhammad Ali versus Sonny Liston
At the pre-fight weigh-in, Clay's pulse rate was around 120, more than double his norm of 54. Liston, among others, misread this as nervousness. In the opening rounds, Clay's speed kept him away from Liston's powerful head and body shots, as he used his height advantage to beat Liston to the punch with his own lightning-quick jab.
By the third round, Clay was ahead on points and had opened a cut under Liston's eye. Liston regained some ground in the fourth, as Clay was blinded by a substance in his eyes. It is unconfirmed whether this was something used to close Liston's cuts, or deliberately applied to Liston's gloves; however, Bert Sugar (author, boxing historian and insider) has recalled at least two other Liston fights in which a similar situation occurred, suggesting the possibility that the Liston corner deliberately attempted to cheat.
Liston began the fourth round looking to put away the challenger. As Clay struggled to recover his vision, he sought to escape Liston's offensive. He was able to keep out of range until his sweat and tears rinsed the substance from his eyes, responding with a flurry of combinations near the end of the fifth round. By the sixth, he was looking for a finish and dominated Liston. Then, Liston shocked the boxing world when he failed to answer the bell for the seventh round, later claiming a shoulder injury as the reason. At the end of the fight, Clay boasted to the press that doubted him before the match, proclaiming, "I shook up the world!"
When Clay beat Liston, he was the youngest boxer (age 22) ever to take the title from a reigning heavyweight champion, a mark that stood until the mid 1980s. At the time, Floyd Patterson (dethroned by Liston) had been the youngest heavyweight champ ever (age 21), but he won the title during an elimination tournament following Rocky Marciano's retirement by defeating Archie Moore, the light-heavyweight champion at the time.