Florence Farley, a girl from Santa Monica, California in her late teens, and a tennis prodigy, is torn between fulfilling the dreams of her ambitious mother Millie, who has planned her tennis career, or her own dreams of being with the man she loves.
Florence has a chance meeting with Gordon McKay, the nephew of a wealthy town figure. Invited to play tennis at the local country club, she defeats him easily. Her prowess at the game causes J.R. Carpenter, the country club's manager, to offer Florence a membership there, plus a trip to Philadelphia to compete for the national junior championship.
Her scheming, social-climbing mother Millie manages to include herself on the trip, leaving her ill husband Will behind. She flirts with Florence's new coach Fletcher Locke and accepts money and gifts, which could endanger her daughter's amateur status. Once Millie realizes that Gordon is not wealthy, she discourages Florence from entertaining the idea of marrying him.
After winning at Forest Hills, an increasingly unhappy Florence wants to retire from tennis and get married. Her father, on his death bed, scolds Millie for looking out for her own interests rather than their girl's. Florence wins the Wimbledon women's singles title, then abruptly quits the game, announcing her impending marriage to Gordon and leaving her mother a forlorn figure on the sideline.