A bellhop becomes a prize fighter and falls in love with his manager's daughter while his manager's girlfriend falls in love with him.
Nick Donati (Edward G. Robinson) drops his boxer after he loses, and girlfriend Fluff Phillips (Bette Davis) soothes Nick. At a party Nick hires bellhop Ward Guisenberry (Wayne Morris) to serve drinks, and Fluff shows him how to mix them. Nick gets jealous, and Silver Jackson (Harry Carey) tells Nick that his boxer was bribed by Turkey Morgan (Humphrey Bogart) to lose. Morgan and his boxer Chuck McGraw (William Haade) come in. When Morgan's girlfriend kisses Ward, Morgan cuts his pants short. Fluff intervenes, and Ward knocks down McGraw. Nick arranges a fight for Ward, and Fluff calls him Kid Galahad. Fluff warns Galahad that it is a rotten business, but he wants money to buy a farm. Galahad fights McGraw's brother. Trainer Silver coaches him, and while Fluff is asking Nick to stop it, Galahad wins. Nick sends Galahad out of town. Morgan tries to sign him up, but Galahad knocks him down.
Silver takes Galahad to the farm of Nick's mother (Soledad Jiménez), and he meets Nick's sister Marie Donati (Jane Bryan). Galahad tells Marie about Fluff, and they argue. Nick arrives to protect Marie and take Galahad back to New York, warning him not to see her. Galahad wins ten fights in a row. Marie hopes to see him again. Silver tells Fluff that Galahad may be in love and gives him two days off. Galahad tells Fluff that he is in love with Marie, and Fluff tells him to go see her. Fluff tells Nick that she is leaving, because she is in love with Galahad, and he is not in love with her. Galahad goes to Marie and proposes. Nick asks Galahad about Fluff and tells him not to knock out O'Brien. Morgan tells O'Brien to get Galahad angry by mentioning Fluff, causing Galahad to knock him out. Nick declines to fight McGraw until next year. Galahad finds Marie and takes her to hear Fluff sing. Morgan finds McGraw drinking. McGraw sees Galahad and pushes him down. Galahad agrees to fight McGraw next month. Fluff asks an editor not to print the photo of Nick's sister, helping identify it. Nick sees it and catches Galahad with Marie. Nick complains, and they say they love each other. Galahad defends Marie by socking Nick.
Nick schedules the title fight and tells Galahad to come out punching. Morgan asks Nick why he bet $50,000 against Galahad, and Galahad bets $150,000 on McGraw. Marie tells Fluff this is Galahad's last fight. Galahad is knocked down several times, and Nick fires Silver for trying to change tactics. Fluff tells Nick that Galahad is getting killed, and Marie pleads with him. Nick bets $50,000 on Galahad and tells him to change tactics, getting Silver back. Galahad is knocked down but gets up and wins. Morgan sends Archie to kill Nick and shoots someone to draw away police. Nick rushes Morgan, shoots him, and is shot. Marie cries, and Nick tells her he was wrong. Fluff comforts Nick as he dies.
This drama contrasts the violence of the fight racket with the purity Nick tries to preserve for his family, a conflict combined in a knight like Galahad. Both managers used crooked strategies; because of the greater violence of Morgan, both are killed for their crimes.