50 years ago, Muhammad Ali became world heavyweight champion

He was still going by the name Cassius Clay. Four years earlier, he'd won Olympic gold in Rome. The future Muhammad Ali had just turned 22, five weeks before he stepped into the ring with world heavyweight champion Sonny Liston.

And he wasn't supposed to win. Two years prior, Liston had had smashed reigning champion Floyd Patterson in two minutes and six seconds to claim the throne, and a rematch didn't go much better for the ex-champ, as Patterson lasted 2:10 before the fight was over. "It will last longer than the Patterson fight," the New York World-Telegraph's Lester Bromberg wrote of Liston-Clay, "almost the entire first round."

Neither Liston nor Clay were press favorites. Liston was described by writers of the time as a thug and criminal -- often in thinly-veiled racist terms -- due to having served time in prison, where he learned to box. Clay, a big-mouthed braggart, also rubbed the white establishment the wrong way. 43 of 46 ringside reporters picked Liston to win by knockout. Clay was a 7-to-1 underdog.

Murray Kempton wrote, "Liston used to be a hoodlum; now he is our cop; he was the big Negro we pay to keep sassy Negroes in line."

Clay taunted Liston constantly in the build-up to the fight, bringing the press with him to Liston's house to deliver the signed contract, and frequently referring to him as "the big, ugly bear." On fight night, Clay backed up his boasts, and established himself as the fighter who would go on to be universally known as "The Greatest."

Though Liston had his moments and some chances, he retired from the fight after round six.

It was one of the great upsets in boxing history, and one of the sport's most memorable events. (Hard to imagine that the promoter of the fight actually lost $300,000 on the event.)

Their rematch in 1965 ended in one round on the so-called "Phantom Punch," but the '64 fight was also suspected of foul play by the FBI, though no conclusive evidence was found. There was, however, a thorough investigation.

HBO Sports' Bryant Gumbel shares his thoughts on Real Sports with Bryant Gumbel, airing tonight at 10:00 pm EST:

"Finally tonight, no rants, no howls of protest about the increasing inequities in sports - just a few words from the Arizona desert, where I'm happy to report, a special man is still enjoying his very special life.

"Despite the rigors of age, the progressive nature of Parkinson's, and some spinal difficulties that have impacted his gait and his balance, Muhammad Ali, according to his wife Lonnie, is doing OK in Arizona. She says she can tell because her husband is still feisty and is still flirting and that recently he actually joked about making a comeback. If only that were possible.

"What prompted my call was the fact that tonight marks the 50th anniversary of the champ's first title; when, as Cassius Clay, he took the heavyweight crown from Sonny Liston on February 25, 1964.

"When I asked Lonnie if they were marking the occasion in any way, she said no. That although Ali enjoys hearing about his past, he doesn't live in it. It's left for those who love him, to mark his golden anniversary in his golden years. It was the first of many unforgettable memories authored by the man who was, and always will be for me and millions of others, still the greatest of all time."