ST. LOUIS -- The St. Louis Cardinals moved a step closer to the National League Central title while eliminating the preseason darling Washington Nationals from playoff contention Monday.
Adam Wainwright worked into the eighth inning for his 18th win, and the Cardinals handed the Nationals a killing 4-3 defeat.
Wainwright allowed seven hits and three runs while walking none and fanning five in seven-plus innings. Four relievers combined to pick up the last six outs, with Trevor Rosenthal retiring the final two hitters for his first major league save.
Tanner Roark (7-1) absorbed his first big league loss, yielding nine hits and four runs in five innings. Washington (84-73) lost for just the fourth time in 17 games but was knocked out when both the Pittsburgh Pirates and Cincinnati Reds won. The Pirates and Reds are assured of at least wild-card playoff berths.
The Nationals missed on a glorious chance to tie or take the lead in the eighth. After leadoff singles by Anthony Rendon and Steve Lombardozzi knocked out Wainwright, Denard Span bunted the runners to second and third against Randy Choate.
Ryan Zimmerman grounded out to short, scoring Rendon, and Jayson Werth bounced out to third to strand Lombardozzi at second.
The win kept St. Louis (92-65) two games ahead of the Pirates and Reds in the National League Central. The Cardinals' magic number for winning the division title is four.
Washington jumped to a quick 2-0 lead in the top of the first on Werth's 24th homer, a 439-foot blast that almost reached the second deck in left field. The homer scored Span, who led off with a single.
St. Louis answered with a run in its half of the first on a two-out, two-strike RBI single to center by Yadier Molina. Matt Carpenter scored his major-league-high 124th run.
The Cardinals evened the score with three consecutive singles in the fourth. Shane Robinson's blooper down the right field line plated David Freese with the equalizer.
Carlos Beltran gave St. Louis a 4-2 lead in the fifth with his 24th homer, a two-run shot into the Cardinals' bullpen in right-center.
NOTES: The Busch Stadium outfield was almost completely resodded with 13 truckloads of grass after it was torn up by a college football game Saturday between Southern Illinois and Southeast Missouri State. There were football markings still visible from foul ground behind first base all the way to the left field corner. ... St. Louis LF Matt Holliday was scratched just before game time and replaced by Robinson. Holliday also missed Sunday night's game due to back spasms. ... Washington finished its home schedule Sunday night and drew 2,652,422 for the year, its highest attendance since opening Nationals Park in 2008. The total represented a 9.1 percent increase compared to 2012.