In 2003, Mussina was third in the league in strikeouts/9 IP (8.18) and strikeout/walk ratio (4.88), fourth in strikeouts (195) and walks/9 IP (1.68), fifth in wins (17), and eighth in ERA (3.40). He held batters to a .190 batting average when there were two outs and runners in scoring position. During Game 7 of the 2003 ALCS, Mussina authored one of the greatest clutch pitching performances of all time. With the Yankees trailing Boston 4–0, Mussina made the first relief appearance of his career. With runners on the corners and nobody out, Mussina struck out Jason Varitek before inducing Johnny Damon to hit into a double play. Mussina went on to pitch 2 more scoreless innings and kept the Yankees within striking distance in a game they later came back to win.