ST. LOUIS -- Chicago Cubs manager Joe Maddon gives leadoff hitter Dexter Fowler simple instructions before every at-bat.

"You go, we go," Maddon says.

Fowler went deep with his first at-bat Monday and Chicago was off and running, administering a 9-0 beatdown of the St. Louis Cardinals at sold-out Busch Stadium.

The Cubs' center fielder lined a 390-foot homer off Lance Lynn (11-9) to set the day's tone, then added a two-run double an inning later that made it 3-0.

It set the tone both ways. Lynn didn't make it out of the third inning as Chicago (79-57) tacked on five runs for an 8-0 lead and never looked back en route to a fourth straight win that further solidified its playoff position.

With Pittsburgh's 3-1 loss in Cincinnati, the Cubs moved within two games of the Pirates for the first wild-card spot, which would carry with it a home game on Oct. 7. The Cubs also pulled within 7 1/2 games of St. Louis (87-50).

"The first goal is to win the division," Maddon said. "But, to do that, you have to catch the next team in front of you, and that's Pittsburgh."

Making his first start since suffering an ankle injury Aug. 29 in the eighth inning of a 6-0 win in San Francisco, Lynn clearly didn't have his stuff. He was tagged for seven hits and six runs over 2 1/3 innings, walking two and striking out two.

"I just didn't have any command," he said. "The ball was all over the place. When I started making pitches, they were already locked in and I couldn't do anything about it."

First baseman Anthony Rizzo's RBI double kicked off the third inning, and catcher Miguel Montero sent Lynn to the showers with a run-scoring single two hitters later. After winning pitcher Dan Haren extended the inning with a two-out single, shortstop Addison Russell cracked a three-run homer, his 13th.

"I was hoping that would be a double," Russell said of his drive, which barely cleared the wall in left-center.

Given a huge lead, Haren (9-9) did what he needed to -- he threw strikes, kept the ball in the park and didn't give the Cardinals a chance to rally. In seven innings, the veteran scattered seven hits, walked two and struck out five.

"Obviously, being out there with a lead like that was the reason I was out there so long," Haren said. "The guys played great defense behind me. Having a lead like that, I'm able to be more aggressive and I can throw more strikes."

Haren tacked on the last run in the fifth with a sacrifice fly. After that, the game took on a spring training feel as St. Louis manager Mike Matheny began hooking starters.

Five of the starting position players departed before the eighth inning, and Maddon also pulled many of his starters before the last out.

It was the fourth loss in five games for the Cardinals, although they maintained their 5 1/2-game lead in the division over Pittsburgh. Their last three defeats have occurred by a combined 21 runs.

"We've been so accustomed to seeing that starting pitching so locked down that when we don't see it it looks extremely odd," Matheny said. "Today was one of those days."

NOTES: Chicago recalled RHP Carl Edwards and LHP Zac Rosscup from Triple-A Iowa to beef up its bullpen. Edwards is 5-3 with a 2.74 ERA and six saves between Iowa and Double-A Tennessee, while Rosscup is 2-1 with a 4.18 ERA in 27 games with the Cubs. ... St. Louis RHP Adam Wainwright (Achilles) threw a light bullpen session Monday as he continues his rehab from an injury that occurred April 25 in Milwaukee. Odds are still against Wainwright returning before season's end. ... Chicago C Kyle Schwarber (right rib cage strain) missed his fifth straight game and might not return until the Cubs hit Philadelphia on Thursday night. ... Cardinals 2B Kolten Wong (calf tightness) was a late scratch. Matt Carpenter moved from third to second, with Mark Reynolds getting the start at third.