The Social Lion (movie, 1930)

Marco Perkins is a garage mechanic and a would-be-prizefighter who gets a place on the ritzy country club's polo team because he is the town's most proficient mallet-wielder, having learned to play polo while serving in the U.S. army. His hobnobbing with the town-elite and social upper-crust at the polo-matches gives him an inflated idea of his social position, and he decides he is is moving on up. He breaks off with his girl-friend, true-blue Cynthia Brown, and hits on débutante Gloria Staunton, who appears to have an interest in being hit upon. Gloria's interest lies mostly in showing Marco that hired-hands who can play polo still aren't to the manor born.