Cardinals 2, Nationals 0

WASHINGTON -- St. Louis ace Adam Wainwright dominated the scuffling Washington offense, allowing just five hits in 8 1/3 innings as the Cardinals scratched out a 2-0 victory Tuesday over the slumping Nationals.

Wainwright (4-1) barely broke a sweat through most of the game, only running into trouble in the sixth inning, when the Nationals loaded the bases with two singles and a walk to Bryce Harper -- Wainwright's first free pass of the season.

But the Cardinals' starter struck out Adam LaRoche for the third time, firing a rising fastball past the Nationals' cleanup hitter, to get out of the jam.

Wainwright nearly tossed his second complete game of the season, but a Harper double to lead off the ninth and a rising pitch count kept him from doing so. However, he did close his night by striking out LaRoche for the fourth time before giving way to Edward Mujica, who picked up his third save by registering the final two outs.

Wainwright entered the game a pedestrian 1-2 with a 6.00 ERA in five career games in Washington, but was in command early, striking out six Nationals hitters during the first four innings.

Washington has now lost four or five overall and five straight at Nationals Park to fall to .500 in a season with World Series aspirations. The Cardinals have won consecutive games for the first time since a four-game streak from April 9-13.

Ross Detwiler (1-1) was the hard-luck loser for Washington, who gave up two runs in six innings of work. The lefty only has allowed five runs in four starts.

St. Louis broke open a pitcher's duel in the fourth inning by stringing four straight hits off Washington starter Ross Detwiler, including an RBI double by Allen Craig and a run-scoring single from Carlos Beltran to make it 2-0.

The Nationals kept Detwiler out of more trouble by turning a season-high four double plays over the course of the first five innings, a season-high. In the first, after a Craig single, Detwiler induced a broken-bat grounder to shortstop Ian Desmond, who started a 6-4-3 twin-killing.

In the second frame, after Yadier Molina walked, David Freese's grounder to second was scooped by Danny Espinosa, who shoveled the ball to Desmond to begin a nifty 4-6-3 double play.

And in the third, after Pete Kozma drilled a single to center, Wainwright attempted to bunt, but Washington catcher Kurt Suzuki quickly pounced on it to begin a 2-6-4 double play that left even the Nationals stunned, as they hesitated before coming off the field.

Wainwright didn't need much defensive help, as he cruised through the struggling Washington lineup with relative ease, allowing just a first-inning single to Bryce Harper through the first five innings.

NOTES: Cardinals CF Jon Jay, in the midst of a 2-for-23 skid, was benched Tuesday and replaced in the lineup by Shane Robinson, who batted leadoff. Jay is hitting .197 for the season, but Matheny is confident Jay will turn things around. "He's going to be a big part of what we've got going forward," the Cardinals skipper said. ... Washington closer Rafael Soriano was back with the club after being placed on paternity leave Monday to be with his wife as she gave birth to a boy. ... Nationals manager Davey Johnson admitted his team may be pressing a bit through the first month of the season in response to the lofty expectations. "Everybody is trying to be a little better than they need to be," he said. ... Beltran's RBI single in the fourth extended his hitting streak to eight games, tying a team high.