No. 9 Joe Louis Joe Louis announced his first retirement from boxing in 1949, while he was still the heavyweight champ. Burdened by IRS debt, he returned to the ring in 1950, when he lost to Ezzard Charles. Louis went on to win a few fights before taking on Rocky Marciano in 1951. The Brown Bomber clearly wasn’t the same fighter he had been during his prime, and lost by a knockout in eight rounds. Louis’ comeback was less embarrassing than many boxers’, but the very best are held to a higher standard.