In 1954, Wilhelm was a key piece of the pitching staff that led the 1954 Giants to a world championship. He pitched 111 innings, finishing with a 12–4 record and a 2.10 ERA. During one of Wilhelm's appearances that season, catcher Ray Katt committed four passed balls in one inning to set the major league record; the record has subsequently been tied twice. When Stan Musial set a record by hitting five home runs in a doubleheader that year, Wilhelm was pitching in the second game and gave up two of the home runs. The 1954 World Series represented Wilhelm's only career postseason play. He pitched innings over two games, earning a save in the third game. The team won the World Series in a four-game sweep.