Posing as a down-and-out fighter, "Dutch" Grady (Greg McClure) is hired as a sparring boxer for heavyweight-champion Joe Palooka (Joe Kirkwood Jr.and knocks him out in a training bout. Sports reporter Tom Conway (David Bruce), starts a jeering series on his radio program and in the press for Grady to get a title match with the champion. Knobby Walsh (Leon Errol), Palooka's manager, refuses to make the match until Grady beats other contenders first. But after much criticism affects Palooka's box-office receipts, Knobby agrees to the Palooka-Grady fight for the championship. But, on the eve of the bout, Grady's manager Talmadge (Lou Lubin), Conway and Doctor Benson (Taylor Holmes)have Joe drugged, and the Boxing Commissioner vacates his title. Maxine (Lina Romay), a beauty-contest winner, agrees to reveal for $5,000 how Joe was framed. Joe finds her knifed to death when he goes to meet her, and the police think he is the killer.