Josh Harrison belted his first career grand slam and Ryan Zimmerman added a three-run blast as the Washington Nationals rallied from an early five-run deficit for a 12-9 win over the visiting Baltimore Orioles on Saturday.

Baltimore jumped to a 5-0 lead in the first inning on Freddy Galvis' RBI double and Ryan Mountcastle's grand slam to left field off Jon Lester.

Zimmerman had three hits and scored three runs for the Nationals, who opened the three-game series with a 4-2 win on Friday.

Lester allowed six runs on five hits over four innings.

Austin Voth followed Lester, allowing one run in two innings of relief.

Daniel Hudson (3-0) earned the win, pitching a scoreless eighth inning, and Brad Hand threw a scoreless ninth for his sixth save in eight opportunities.

Orioles right fielder Anthony Santander went 3-for-4 with a walk and home run. Santander also scored three runs for Baltimore, which has lost five straight and 12 of its past 14 games.

Washington trailed 6-1 in the middle of the third before responding with eight runs over the next two innings. Harrison cleared the bases with one out in the third with a grand slam off Bruce Zimmermann, who allowed five runs on seven hits over three innings.

The Nationals scored four runs again in the fourth inning, moving ahead 9-6 when Trea Turner doubled in a run and Zimmerman crushed a 436-foot three-run homer off Adam Plutko.

Santander, playing in his second game since returning from the injured list, cut the lead to 9-7 with his solo homer in the fifth off Voth.

The Nationals extended their lead with three runs in the sixth. Starlin Castro's sacrifice fly scored Juan Soto, who doubled to begin the inning. Kyle Schwarber followed with an RBI single, and the Nationals added another run when Yadiel Hernandez scored from third on Maikel Franco's throwing error.

Soto went 2-for-4 with three runs scored and is 9-for-21 with a home run in his past five games.

After recording a total of six hits in its previous two games, Baltimore erupted for 12 on Saturday. Pat Valaika brought the Orioles to within 12-9 with a two-run double in the eighth.

Baltimore first baseman Trey Mancini went hitless in four at-bats, ending his hitting streak at eight games.

--Field Level Media