Washington, DC (SportsNetwork.com) - Michael Wacha outdueled Max Scherzer by twirling seven outstanding innings, and Matt Adams singled in the deciding run in the St. Louis Cardinals' 4-1 win over the Washington Nationals.

Wacha (3-0) held Washington to a run on five hits and struck out six to win his third consecutive start and lead the Cardinals to a seventh victory in eight games.

"I thought he had everything (working) as much as he's had everything so far this season," Cardinals manager Mike Matheny said of Wacha. "Everything looked very sharp."

Matt Carpenter and Jason Heyward each finished 2-for-4 for St. Louis, with Heyward scoring the go-ahead run on Adams' two-out single off Scherzer that snapped a 1-1 deadlock in the sixth inning.

The hit helped deal Scherzer (1-2) a second loss in four outings despite the prized free-agent addition yielding just two runs over seven innings of work.

"Overall I felt I did pretty well, I kept us in the game for the most part," Scherzer said. "But there was obviously things I wish I could have done better."

Denard Span drove in the Nationals' lone run with a single in the rubber game of this three-game series.

Adams atoned for a defensive lapse in the fifth inning that helped Washington tie the game at 1-1. Stepping to the plate with two on and two out in the sixth, the big first baseman inside-outed a Scherzer pitch to left field for a single that brought home Heyward and sent the Cardinals in front.

Wacha made the lead stick by setting down nine straight hitters after Span's RBI single in the fifth, and Mark Reynolds put St. Louis further in front with a pinch-hit RBI double that followed Matt Holliday's single in the eighth.

Reynolds scored as well on the play when Nationals reliever Aaron Barrett air- mailed the ball to second after retrieving Espinosa's errant throw to the plate while attempting to nab Holliday.

Jordan Walden and Trevor Rosenthal finished out the game for St. Louis, with the latter tossing a perfect ninth to record his sixth save.

An aggressive St. Louis lineup jumped on Scherzer early, as Carpenter doubled on the game's first pitch, raced to third on a base hit from Heyward and crossed the plate when Scherzer skipped a pitch in the dirt for a wild pitch.

"I think we had a pretty good plan against him, going out there and being aggressive early," Adams said of Scherzer. "Whether it's a fastball or his secondary stuff, he throws strikes with it, so we were ready for it."

Scherzer rebounded to retire 16 of the next 17 batters following Heyward's single, and the Nationals cashed in on Danny Espinosa's leadoff double in the fifth to draw even.

Espinosa's hit was preceded by Scherzer's seemingly harmless grounder to short, but Adams had his foot off the bag while taking Jhonny Peralta's throw for an error that placed runners at the corners. Span laced the next pitch for a single to right that knotted the score at 1-1.

Game Notes

Carpenter is batting .429 (18-for-42) with 11 runs scored and 10 RBI over a 10-game hitting streak ... Wacha has allowed just two earned runs over 22 2/3 innings in three lifetime starts against the Nationals ... Washington's Ian Desmond doubled in the eighth inning to extend his hitting streak to nine games ... Scherzer, a St. Louis-area native, was facing the Cardinals for the first time since 2009, while then with the Arizona Diamondbacks ... Since Game 5 of the 2012 National League Division Series, the Cardinals have won 13 of 16 meetings with Washington.