Nationals 4, Astros 3: Adam LaRoche delivered a game-tying RBI double in the eighth inning and singled in the go-ahead run in the ninth as visiting Washington rallied to take the opener of a two-game interleague series.

Jayson Werth homered and scored twice while Jose Lobaton recorded a run-scoring double for the Nationals, who have won five straight against Houston. Tyler Clippard (2-2) threw a scoreless eighth for the win and Rafael Soriano worked around a pair of two-out walks to record his fifth save in as many chances.

The Astros did all of their damage in the third against Washington starter Gio Gonzalez as Dexter Fowler ripped an RBI single and George Springer followed with a base hit to score two runs. Astros starter Jarred Cosart allowed two runs in six innings and was in line for the win before Anthony Bass was charged with the tying run and Josh Fields (0-3) gave up the go-ahead tally for his third loss in seven days.

Werth singled to lead off the eighth and came all the way around when LaRoche's drive to left-center was just out of the reach of Fowler against the wall. Denard Span walked on four pitches to lead off the ninth, stole second and later scored the decisive run when LaRoche lined a base hit to right.

Werth homered on an 0-2 hanger from Cosart in the first and Lobaton delivered an RBI double in the third to give Washington a 2-0 lead. Gonzalez allowed three runs and struck out a season-high nine in six innings.

GAME NOTEBOOK: Nationals OF Bryce Harper had surgery Tuesday to repair the torn ligament in his left thumb. He is expected to be out until July. ... Washington optioned RH Taylor Jordan to Triple-A Syracuse and recalled RH Ryan Mattheus. ... Fowler extended his hitting streak to nine games with his third-inning single.