Stan Musial . Spring Training . St. Petersburg, Florida . 1957
AP Photo
May 2, 1954 - Stan Musial of the St. Louis Cardinals set a major league record of five home runs in a doubleheader against the New York Giants at Sportsman’s Park in St. Louis.
(Nate Colbert of the San Diego Padres would go on to duplicate the feat in a twin bill against the Atlanta Braves in 1972)