The Duke Comes Back (film)

The Duke Comes Back is a 1937 American drama film directed by Irving Pichel and written by Adele Buffington and Edmond Seward. It is based on the 1933 novel "The Duke Comes Back" by Lucian Cary. The film stars Allan Lane, Heather Angel, Genevieve Tobin, Johnny Russell, Joseph Crehan and Frederick Burton. The film was released on November 29, 1937, by Republic Pictures.
Plot.
Duke Foster dethrones boxing's heavyweight champion, then promptly announces his engagement to Susan Corbin, a high-society girl whose financier father, Arnold Corbin, disapproves of her choice in men. Susan's sensible sister Pauline persuades their father the marriage will be fine and becomes Duke's partner in a publishing business so that he can quit fighting. Four years pass and the Fosters have a son, Jimmy.
Arnold embezzles and loses $200,000 and faces prison. Duke decides to try to raise the money by boxing again. A corrupt promoter, Jim Watson, bets a bundle on Duke's opponent, Bronski, and has Susan and her son taken hostage. Duke is warned to lose the fight, but doesn't believe the threat is true. Al goes to the arena to shoot Duke before he can win the bout and lose Watson's wager, but Al is overpowered, Duke wins and his family is safe.