The Giants entered the series as slight favorites due to the MVP season of Kevin Mitchell, the solid play of Will Clark, and the best ERA in baseball by pitcher Scott Garrelts. The Cubs had won their second NL East title in six seasons behind the excellent rookie performances of Jerome Walton and Dwight Smith, who finished one-two in the 1989 NL Rookie of the Year balloting. The Cubs also had three pitchers with sixteen or more victories, Rick Sutcliffe, Mike Bielecki, and Greg Maddux, coming off his third full season in the majors. The opener pitted Maddux against Garrelts.

By the time the Cubs came to bat, the Giants led, 3–0. Brett Butler led off with a single and moved to third on Rick Wrona's passed ball. Clark drove in his first run of the series with a double. Clark moved to third on Mitchell's single and scored along with Mitchell on Matt Williams' double. Maddux had given up three runs and recorded only one out, but he retired Terry Kennedy and Pat Sheridan to end the first. The Cubs came right back in the bottom of the first. Ryne Sandberg doubled and Mark Grace drilled a two-out, two-run homer to cut the Giants lead to 3–2. Clark got a run back when he homered in the third, but Sandberg's solo homer cut the Giants lead back to one. With the score 4–3, the Giants came to bat against Maddux in the fourth.

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Wikipedia