Ferriss then compiled a 25–6 record (the best in the AL) that helped the Red Sox win the AL pennant in 1946. He was selected for the All-Star Game that season for the first and only time but did not pitch (the 1945 All-Star Game had been cancelled due to World War II). He started two games in the 1946 World Series against the St. Louis Cardinals, and pitched a complete-game shutout in the third game before getting a no-decision in the seventh and deciding game, which was won by the Cardinals.