WASHINGTON -- First baseman Matt Adams' sixth-inning RBI single proved to be the difference Thursday in a pitchers' duel as the St. Louis Cardinals picked up a 4-1 victory over the Washington Nationals to capture the rubber game of a closely contested series.

Adams continued to torment Washington pitching, boosting his career RBI total to 11 in just 12 games against the Nationals.

The sixth-inning rally started when right fielder Jason Heyward singled against Washington starter Max Scherzer (1-2), who then hit left fielder Matt Holliday to move a Cardinals runner into scoring position for just the second time in the game. Adams followed with a sharp single to left to break a 1-1 tie.

In the eighth, Cardinals pinch-hitter Mark Reynolds drove a ball deep into the right-center gap and Washington committed two throwing errors, allowing both Holliday, who had singled one batter before, and Reynolds to score.

St. Louis starter Michael Wacha improved to 3-0, keeping the Nationals in check for most of the game. His only blip came in the fifth inning when second baseman Danny Espinosa led off with a ringing double off the right field wall, Scherzer reached on an error by Adams and center fielder Denard Span laced an RBI single to right to tie the score at 1.

The Cardinals opened the scoring in the first inning thanks to some early wildness from Scherzer, who allowed base hits to the first two batters and then uncorked a wild pitch that allowed Matt Carpenter to trot home from third base.

Cardinals closer Trevor Rosenthal retired the side in order in the ninth to pick up his sixth save of the season.

NOTES: Nationals OF Jayson Werth was not in the starting lineup Thursday, a move manager Matt Williams said was based on keeping him fresh after he missed spring training and the first week of the season with a shoulder injury. "He's going to have to have an occasional day," Williams said. ... Cardinals OF Jason Heyward has gotten off to a slow start at the plate, but manager Mike Matheny said the new acquisition's output goes beyond batting average. "That's not the biggest indicator for us. We like what he's doing," Matheny said. ... Cardinals OF Peter Bourjos will return to the team Friday after missing the last three games for the birth of his child. ... Nationals 3B Anthony Rendon (knee) will begin a rehab assignment Friday at Double-A Harrisburg. ... Washington will open a three-game series at Miami on Friday, with Jordan Zimmermann (1-2) opposing Mat Latos (0-3). St. Louis will travel to Milwaukee, where Carlos Martinez (1-0) will face Matt Garza (1-2).