The 1984 Cubs made the franchise's first postseason appearance since 1945, and were the first of only two playoff teams that Smith played for (the other being the 1988 Red Sox). Smith saved more than 30 games for the first time in his career, but compiled a 3.65 ERA, his worst of the decade. In the postseason, he appeared in two games of the NL Championship Series. In Game 2, Smith earned the save in a 4–2 Cubs win by recording the final two outs. The win gave the Cubs a two-games-to-none lead in the best-of-five series, but the San Diego Padres won the next three games to deny the Cubs a berth in the 1984 World Series. Smith took the loss in Game 4: entering in the bottom of the eighth with the game tied, 5–5, he allowed one hit and kept the game tied; in the bottom of the ninth, he allowed a one-out single to Tony Gwynn, followed by a two-run walk-off home run by Steve Garvey to force a deciding fifth game. Smith did not pitch in Game 5; while Chicago held a 3–0 lead after the second inning, San Diego score six unanswered runs for a 6–3 final. Of Smith's eight seasons with the Cubs (1980–1987), this was the only year the Cubs had a winning record, and the only time they finished higher than fourth in their division.