Efforts to control the influenza pandemic of 1918–1919 were in the hands of local officials, creating a mosaic of regulations. Among the aspects of society affected by these regulations were organized sports, which attracted large groups of people that could contribute to the spread of the disease. Infection rates were highest during the cooler months, so baseball was largely unaffected. However, southern California had an active winter baseball season that attracted major league players, who earned money by playing for teams such as the Pasadena Merchants. Pasadena and the Standard-Murphy team from the oil field region near Whittier were in the midst of a five-game series for the self-proclaimed semipro championship of southern California, when the Pasadena City Commission passed an ordinance requiring everyone to wear a cloth face mask in public. Baseball players would not be exempt, and they refused to play under these conditions. However, instead of moving the game to another city, the players changed their minds and donned the masks on 26 January 1919 for what turned out to be an 11-inning contest. The novelty of the game attracted photographers, and news of the event was reported by newspapers across the country. Four days later, the mask ordinance in Pasadena was rescinded. This narrative summarizes the events surrounding this game, in which several major league players participated.