Fictional aging heavyweight Louis Mountain Rivera (Anthony Quinn) is felled by young Cassius Clay, the future Muhammad Ali, and finds his professional career over. His manipulative manager (Jackie Gleason) owes money on bets placed against Rivera, and convinces him to become a wrestler. Humiliated by the notion, Rivera examines the few options available in the afterglow of a boxing career. Rivera is broken and battered, but he continues to have the support of his trainer (Mickey Rooney).