After lightweight prizefighter Kid Mason (Ayres) loses his opening fight, golddigging wife Rose (Harlow) leaves him for Hollywood. Without her around, Mason trains seriously and starts winning. Naturally, Rose returns and worms her way back into his life, despite the misgivings of manager George Regan (Armstrong). Eventually, she cons Mason into dumping Regan and replacing him with her secret lover Lewis (Miljan), even though he has almost no experience in the fight game. To make matters worse, Mason's high living and neglect of his training threatens his latest title defense.