
Wilson Ramos also hit a two-run double in the second for the Nats (26-16).
Tanner Roark (3-3, 2.89 ERA) gave up a run on six hits in six and two-thirds innings, striking out seven and walking two.
Jonathan Papelbon gave up a hit in a scoreless ninth to record his 12th save.
Jayson Werth and Anthony Rendon each had two hits for Washington, which has won three in a row and has a two-game lead on Philadelphia in the National League East.