02/26/2013 12:09 am ET

Cassius Clay Defeats Sonny Liston To Win Heavyweight Title On February 25, 1964 (VIDEO)

Before the world agreed that Muhammad Ali was "the greatest," 22-year-old Cassius Clay was a challenger who needed to back up his braggadocious talk.

On February 25, 1965, the young Olympic champion stepped into the ring in Miami, Florida with heavyweight champion Sonny Liston for the first time in his storied career. Clay claimed victory when Liston couldn't return for the seventh round.

"All those interminable refrains of 'float like a butterfly, sting like a bee,' had been more than foolish songs," Robert Lipsyte wrote for The New York Times after Clay's landmark triumph.