In 1957, Larsen had a 10–4 record with 3.74 ERA in 27 games, 20 of them starts. Larsen again had a bad start to the season, giving out four earned runs in innings pitched in his opening start against the Boston Red Sox. He gave up three consecutive hits to Gene Stephens, Gene Mauch and Sammy White to start the second inning, and after a sacrifice fly by pitcher Bob Porterfield, he gave up a double to Frank Malzone, knocking Larsen out of the game. On May 26, Larsen gave up four earned runs in less than one inning of work in a start against the Washington Senators. He started another game two days later against the Red Sox and by the end of the month his ERA was over 6. He improved by the end of the season, hurling a 3-hit shutout against the Kansas City Athletics on September 15. In the 1957 World Series against the Milwaukee Braves, he pitched seven innings in relief in Game 3, getting the win in a 12–3 lopsided defeat. He started the seventh game of the Series, lasting innings in a 5–0 loss as the Braves won the Series.