A weird quirk of baseball is that games can be considered complete even if they don’t actually finish nine innings. Shortened games (almost always due to rain nowadays) can occur if five innings are completed. That can create some weird statistical happenings, such as David Phelps’ only career complete game, when he got through all five innings in a rain-shortened contest in 2014.
On August 31, 1906, the Yankees, then known as the Highlanders, played a shortened game against the Washington Senators. However, if you were just glancing at the schedule, looking at the scores, you might not know that.