ST. LOUIS -- If the Chicago Cubs bought champagne at any point during this nine-game road trip, it's going back to Wrigley Field with them after Wednesday's series finale with the St. Louis Cardinals in Busch Stadium.

St. Louis' 4-2 victory Tuesday night not only kept it a half-game behind the New York Mets for the National League's second wild-card spot, it kept Chicago's magic number for clinching the NL Central at three.

That means the Cubs (92-52) can't celebrate a division title on the field of their biggest rivals, although there's no reason to worry about a 16-game lead with 18 games remaining.

"It's going to happen," center fielder Dexter Fowler said. "It's just a matter of when. So we just have to keep winning games."

Chicago shoots for its 93rd victory Wednesday behind left-hander Jon Lester, who has been on some roll in the last month. Lester (16-4, 2.51 ERA) fired seven shutout innings Friday night in Houston, posting a 2-0 win.

It was the fifth straight game that Lester had allowed one or no runs. Lester, who faced the Cardinals last month at home and was no-decisioned after allowing two runs in six innings, is 1-3 with a 2.62 ERA in seven regular season outings against them.

St. Louis counters with its top starter this year, right-hander Carlos Martinez (14-7, 3.05). He's won his last four decisions, including a 4-3 verdict Friday night over Milwaukee in which he didn't have his best stuff, striking out only one in seven innings.

Martinez gave up three runs (two earned) and nine hits, inducing two more double play balls to give him an NL-high 32 for the year. He's faced the Cubs three times this year, going 1-1.

With every game meaning so much, Cardinals manager Mike Matheny didn't exactly address the subject of trying to prevent a clinching party by Chicago on Monday or Tuesday night.

"We haven't ever gone there," he said. "We just have to go and play the game, not think about anything but what we have to do."

While the odds favor New York and San Francisco, both of whom have easier schedules, St. Louis is getting some key reinforcements for the final three weeks. Shortstop Aledmys Diaz returned to the starting lineup Tuesday night and promptly belted a two-run homer in his first at-bat, becoming the seventh Cardinal with 15 or more homers.

At some point before the week is over, St. Louis is expected to activate right-hander Trevor Rosenthal, right-hander Michael Wacha and left fielder Matt Holliday off the 15-day disabled list. Those moves could beef up its bullpen and add depth to the outfield, depending on Holliday's readiness to play without being able to go on a rehab assignment.

The Cardinals also got a breakout game from Brandon Moss, who was 1-for-41 prior to singling and homering Tuesday night. Moss' two-run homer in the sixth, his 26th of the year, was the game-winning hit.

"You could tell he had a good rhythm going tonight with his early at-bats," Matheny said. "When he gets hot, he's fun to watch."

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.