Boxer Tom "Bomber" Brown wins his eighth victory in the ring. Later, in a nightclub, crooked gambler Morgan blames him for not taking a dive, and he and Tom get in a fight in which Morgan is apparently killed. "Gloomy Gus," Tom's manager, helps him get away, urging him to hitchhike to Chicago to avoid the police. While staying with tramps alongside the road, Tom gets in a fight defending young "Baby Face" Madison, and gives him some boxing tips. After arriving in Chicago, Tom learns that since the death of her father, Nan Howard is now running a gym he used to frequent. Using the name Tom Hayes, he gets a twenty-dollar-a-week job as a gas station attendant, working six days a week so that he can coach Baby Face in his spare time. Baby Face wins his first bout, which Nan had refused to attend despite Tom's invitation. Police question Nan about Tom, but she does not tell them of her suspicions. Promoter Tex Lamont offers Baby Face a championship bout in Madison Square Garden, and although Tom warns him that he is not yet ready, Baby Face rejects Tom and barely trains, fully confident of victory. Baby Face does not know that his opponent, Melford, has been set up to take a fall. Instead, Baby Face is defeated and Slim, his manager, quits. However, when Nan tells Baby Face about Tom, he returns to him. After a period of being unable to find any fights, Baby Face resumes his ascent in the boxing world. As Baby Face heads for New York, where Tom is still wanted by the police, the press becomes suspicious of his secret training. Tom sends for his old manager, Gus, while Nan tries to cover up Baby Face's use of Tom's techniques. Morgan is actually still alive and in the fight game, and offers to turn himself in if Tom and Gus will have Baby Face take a dive. At Madison Square Garden, Baby Face forgets all that Tom has taught him, barely staying in the ring. Finally Tom reveals himself by stepping out of the crowd to encourage Baby Face to achieve victory. Morgan loses $100,000 and is killed by the mob and his death clears Tom, who embraces Nan.