On Sunday night, he came off the bench, ailing shoulder and all, and extended the one they're on.
Pinch-hitter Scott Hairston's sacrifice fly with one out in the 11th inning drove in Werth to give the Nationals a 6-5 victory over the Pittsburgh Pirates on Sunday night and complete a three-game sweep.
Werth, who had missed the last five games due to his sore right shoulder, entered the game as a pinch-hitter in the ninth and doubled leading off the 11th against Brandon Cumpton (3-4).
"I haven't swung a bat for like a week, so there's not a whole lot you can do there," Werth said about keeping his timing sharp. "When you play this long and you play this deep in the season, you don't ... it's like when you come back from the All-Star Break, it's not like you miss a whole lot."
Werth went to third on Denard Span's grounder to first. Hairston then sent Cumpton's first pitch to deep left and Werth scored easily after the catch.
"I (was thinking) just drive the ball to the outfield," Hairston said. "Obviously a hard ground ball can get the job done, too, if it finds a hole, but your percentages are better if you get it to the outfield."
Ross Detwiler (2-2) pitched two innings for the win as Washington won for the second night in a row in its final at-bat.
Span and Anthony Rendon had two hits each for National League East-leading Washington, which has won six straight.
The Pirates were winless on their five-game road trip and have lost five straight for the first time since September 2012.
Both closers blew save chances in the ninth.
Trailing 4-2 entering the inning, the Pirates got one run on a wild pitch and took a 5-4 lead on Gregory Polanco's two-run double off Rafael Soriano.
Washington rallied against Matt Melancon in their half, however. Asdrubal Cabrera's one-out single off the glove of a diving Neil Walker scored Werth, who had walked, from second with the tying run.
"I don't want to come back before I'm ready, but at the same time it felt like we'd progressed enough and felt good enough to get in there," Werth said.
Washington starter Doug Fister allowed two unearned runs in seven innings, and hasn't given up an earned run in his last 22 1/3 innings.
The Nationals trailed 2-1 before a successful challenge started a seventh-inning rally.
A pitch to Michael Taylor was called a foul ball by home plate umpire Andy Fletcher as Taylor started towards first. Manager Matt Williams challenged, saying the 2-1 pitch hit Taylor's hand, and the call was overturned upon review.
Pinch-hitter Kevin Frandsen and Span singled to load the bases. Cabrera, facing reliever Jared Hughes, grounded to first baseman Ike Davis. Davis threw high to home, the ball deflecting off Russell Martin's glove as Taylor scored.
As the ball rolled up the third-base line, Frandsen raced home, putting Washington ahead 3-2.
Rendon then grounded to Pedro Alvarez, who threw high to home for another error, allowing Span to score the Nationals' fourth run.
"We got three ground balls from Hughes in the seventh inning, and an opportunity to put the inning away without letting them score, and we didn't execute plays in either corner," Pirates manager Clint Hurdle said.
Errors by Washington's Ian Desmond and Rendon helped the Pirates take a 2-0 lead in the sixth.
The Nationals cut it to 2-1 in the sixth on Desmond's two-out RBI-single.
Pirates: RHP Charlie Morton was placed on the 15-day disabled list with right hip inflammation.
Pirates: RH Vance Worley (5-2, 2.51) goes against Atlanta on Monday as Pittsburgh opens a three-game homestand. He's 1-2 with a 5.81 ERA in seven career appearances (five starts) against the Braves.
Nationals: Jordan Zimmermann (8-5, 2.92) opposes visiting Arizona in the first of four games. He is 2-0 with a 1.37 ERA in his last three starts.
For game that featured four errors, there were two exceptional defensive plays. In the eighth, Cabrera fielded Russell Martin's grounder behind second and flipped the ball behind his back to Desmond as part of a 1-4-6-3 double play. In the bottom of the ninth, Starling Marte made a diving catch in center to rob Rendon.
Nationals Get Walk-Off Win Against Pirates
Asdrubal Cabrera drove in the tying run in the ninth and Scott Hairston hit a walk-off sac fly in the 11th to lift the Nationals to a 6-5 win against the Pirates.