In Leiter's first season as a Met, he reached a career high in wins going 17–6 and a career low in ERA finishing with a 2.47 ERA. In 1999, when the Mets were tied with the Cincinnati Reds for the National League Wild Card spot after 162 games, Leiter was the Mets starting pitcher in the "winner take all" one game playoff at Cinergy Field in Cincinnati. Leiter pitched a 2-hit complete game shutout to earn the win in the Mets 5–0 victory. The win put the Mets in the playoffs for the first time in 11 seasons. The Mets would go on to lose the 1999 National League Championship Series to the Atlanta Braves 4 games to 2.