WASHINGTON — Foster Griffin struck out nine over seven strong innings for his 10th win of the season, and Luis García Jr. drove in three runs with a two-out homer as the Washington Nationals beat the Houston Astros 8-2 on Wednesday night at Nationals Park to take two of three in the series.

Washington broke through with a two-run third when James Wood walked, stole second and scored on a CJ Abrams sacrifice fly, with Daylen Lile doubling home García Jr. two batters later. The Nationals blew the game open in the fourth: after Keibert Ruiz singled and Wood walked, García Jr. turned around a Spencer Arrighetti pitch and sent it 417 feet to right-center for his 20th homer of the season, a three-run shot that made it 5-0. Abrams led off the fifth with his own 20th homer of the year, a 415-foot blast to right-center, and Washington tacked on two more in the frame on a Jose Tena groundout and a Ruiz sacrifice fly to push the lead to 8-1.

Griffin (10-2) allowed one run on five hits without issuing a walk, tying a career high with nine strikeouts and lowering his ERA to 2.77. It was his seventh straight start allowing one earned run or fewer, and his 10th win is the most by a Nationals rookie since the franchise moved from Montreal in 2005 — a stretch that has him building a case as a potential injury replacement on the National League All-Star team. Oliver Ribalta worked a scoreless ninth to close it out. Arrighetti (7-5) was tagged for eight runs on seven hits over four innings, and Houston’s bullpen issued 10 walks on the night; the Astros’ two runs came on a Brice Matthews RBI single in the fifth and an infield single by Nick Allen in the eighth that scored on a throwing error by Abrams.

The win pushed Washington to 47-46 on the season and clinched the series over Houston. The Nationals are off Thursday before opening a three-game weekend series at home against the New York Yankees on Friday.