Andújar returned to a starting role with the Cardinals and responded by going 6–1 for the rest of the 1981 season. In , he pitched a career high innings. He won his last 7 decisions and had a 1.64 ERA down the stretch to finish the season at 15–10. He pitched a three-hit shutout of the Philadelphia Phillies at Veterans Stadium on September 15 that put his team games up on the Phillies in the National League East, a lead they held for the remainder of the season.