In 1941, his first season as a regular starter, Reiser helped the Dodgers win the pennant for the first time since 1920. He was a sensation that year, winning the National League batting title while leading the league in doubles, triples, runs scored and slugging percentage. He was also named a starter to the All-Star team and placed second in MVP balloting. On July 19 of the following year, Reiser crashed face-first into the outfield wall in St. Louis, trying to catch what turned out to be a game-winning inside-the-park home run by Enos Slaughter of the rival Cardinals in the bottom of the 11th inning. The loss cut the Dodgers' lead over the Cardinals to six games.