CHICAGO (Interstat) — Pete Crow-Armstrong made history, Seiya Suzuki delivered the knockout blow and the Chicago Cubs overpowered the St. Louis Cardinals 12-1 on Friday afternoon at Wrigley Field to move closer to securing home-field advantage for the postseason.

In a game that was a tight contest for six innings, the Cubs erupted for seven runs in the seventh inning, capped by Suzuki’s grand slam, to turn a pitchers’ duel into a laugher before a crowd of 35,611. The victory improved the playoff-bound Cubs to 90-70, while the Cardinals fell to 78-82.

Crow-Armstrong’s two-run homer in the fourth inning was the 30th of his season, making him the first Cubs player ever to record 30 home runs, 30 doubles and 30 stolen bases in a single campaign.

The game was a stark contrast to the projection from Interstat’s game simulator, which had forecast a 6-5 Cardinals victory. The Cubs, who were installed as pregame favorites with a -1.5 spread, easily covered as the total score of 13 sailed over the closing over/under line of 9.

Cubs starter Colin Rea (11-7) was brilliant, earning the win with 5 2/3 scoreless innings. He allowed just two hits and struck out seven, effectively silencing the St. Louis lineup. The Cubs bullpen was equally dominant, with Brad Keller, Andrew Kittredge and Daniel Palencia combining for 3 1/3 innings of scoreless relief, allowing only two hits and striking out six.

Cardinals starter Miles Mikolas (8-11) took the loss, surrendering four runs on four hits over five innings of work.

The scoring started early when Nico Hoerner led off the bottom of the first inning with a solo home run to center field, immediately answering the Cardinals’ first-inning run. The game remained tied until the fourth, when Crow-Armstrong connected for his historic two-run shot to right-center field, scoring Kyle Tucker.

Michael Busch extended the lead to 4-1 in the fifth inning with his team-leading 32nd home run, a solo blast to center.

The contest remained tight until the fateful bottom of the seventh. The Cubs sent 11 men to the plate. The inning started with a Dansby Swanson walk and, after a strikeout, Matt Shaw tripled to left field to score Swanson. Busch followed with an RBI double, and Ian Happ added a run-scoring single. After a walk to Tucker loaded the bases, Suzuki crushed his 30th home of the year, a grand slam to left-center field, making him the third Cub to reach the 30-homer mark this season and pushing the score to 11-1.

Chicago added a final run in the eighth on an RBI single from Kevin Alcántara.

The Cardinals’ lone run came in the seventh inning on an RBI single from Jordan Walker that scored Nolan Gorman, who had doubled.

The Cubs, who had struggled recently by losing six of their previous eight games, trimmed their magic number to one for securing home-field advantage in their opening-round playoff series against the San Diego Padres, which begins Tuesday.

The two teams continue their three-game series Saturday and Sunday to close the regular season.