PHILADELPHIA -- Wilson Ramos drove in the go-ahead run with a seventh-inning single as the Washington Nationals beat the Philadelphia Phillies 2-1 on Wednesday night, completing a sweep of the three-game series.

Former Phillie Jayson Werth homered for the Nationals, who ran their winning streak against the Phillies to nine.

Freddy Galvis homered for the Phillies, who lost for the fifth time in six games.

With the score tied 1-1 and two outs in the top of the seventh, Washington's Anthony Rendon doubled against Adam Morgan (1-9). Ramos fell behind in the count 0-2, battled back to 3-2 and on the eighth pitch of the at-bat singled to right. Rendon beat the throw to the plate by right fielder Aaron Altherr.

Gio Gonzalez (10-9) picked up his fourth straight victory, going six innings and allowing one run on Galvis' homer in the fifth. Gonzalez surrendered just one other hit while striking out four and walking one.

Sean Kelley, the fourth Nationals pitcher, retired the only hitter he faced in the ninth to pick up his seventh save of the season.

Nationals first baseman Ryan Zimmerman contributed three outstanding defensive plays.

The converted third baseman made a leaping grab of Galvis' line drive in the second and dived to his right to snag Maikel Franco's liner in the fifth. In the seventh, Zimmerman ranged far to his right to field Tommy Joseph's grounder, then made an off-balance throw to reliever Blake Treinen for the putout at first.

Morgan pitched 6 2/3 effective innings but nonetheless lost his ninth straight game. Morgan, whose streak spans 12 starts and two relief appearances and dates to May 15, became the first Phillies pitcher to have a losing streak of nine or more since Kyle Abbott dropped 11 in a row in 1992.

Morgan allowed two runs and three hits while striking out five. He didn't walk a batter and departed after surrendering Ramos tiebreaking single.

Werth, hitting with one out in the top of the first, gave Washington a 1-0 lead when he launched Morgan's 3-1 fastball 453 feet to deep center. It was Werth's fourth homer in six games, his eighth in August and his 20th of the season.

Galvis tied it with his 15th homer of the season in the fifth, a solo shot on a 3-2 fastball from Gonzalez.

NOTES: Nationals manager Dusty Baker rested INF-OF Trea Turner, despite the fact that Turner has reached base in 20 straight games. Michael A. Taylor started in center field, Turner's usual spot. Turner entered the game at second base with two outs in the ninth and threw out Maikel Franco at first to end the game. ... Phillies LF Tyler Goeddel made his 52nd start of the season, and his first since Aug. 23. ... Philadelphia manager Pete Mackanin said his club will "most likely" add three players from the minor leagues Friday, when every major league team can expand its roster. Mackanin said the Phillies will probably add "a couple relievers (and) maybe a hitter," and added that other players could be added later in September, after Triple-A Lehigh Valley and Double-A Reading end their seasons. Both are on track to make the playoffs.