Diana Dixon, a Texan girl (played by Diana Dors), wins a quiz show jackpot, and uses her winnings (a prize in cash and a brand new Cadillac car) for a trip to Italy. Her car breaks up near Siena where she meets Prince Piero di Montalcino (Vittorio Gassman), a handsome Italian nobleman. He believes that she must be rich, and she also thinks that he must be wealthy, but that's very far from the truth.<br> The romance reaches its climax at the traditional Palio di Siena horse race where, after Diana breaks up with the prince upon hearing that he bribed the jockey of the rival ''contrade of Siena'' into throwing the race so that his horse could win, she fast-talks the rival horse's owner into letting her ride. After winning the Palio, she will accept to marry the Prince.