Matlack's record dipped to 14–16 in 1973, however, he was 5–1 from August 18 on, helping the Mets capture the National League East crown. Perhaps his most memorable moment with the Mets occurred on October 7, 1973 when he held the "Big Red Machine" to just two hits in Game 2 of the 1973 National League Championship Series. Both hits were by reserve outfielder Andy Kosco.