On October 7, Wacha started his first Major League playoff game. In innings of work in Game 4 of the 2013 National League Division Series (NLDS)—an elimination game against the Pittsburgh Pirates—he again surrendered one hit (a home run) and two walks. Due to Wacha's back-to-back one-hit performances, Matheny announced that he would start Game 2 of the National League Championship Series (NLCS). In that game on October 12, he outdueled Clayton Kershaw in innings for a 1–0 victory over the Los Angeles Dodgers. In just the 11th start of his MLB career, Wacha joined Bob Gibson as the only pitchers in franchise history to strike out at least eight batters while yielding one or no runs in consecutive postseason starts.