Wilson Ramos finished 4-for-4 with a home run and tied a career best by amassing five RBI as Washington downed Philadelphia, 11-2, in the rubber match of a three-game set.
"He's been hitting the heck out of the ball, catching good, throwing people out. He's hard to take out of the lineup," noted Nationals manager Davey Johnson.
Ian Desmond knocked in three runs, while Bryce Harper collected three hits and scored three times for the Nationals, who have won eight of their last nine.
Washington also pulled back within 4 1/2 games of the NL's final wild card berth after Milwaukee topped Cincinnati.
Jordan Zimmermann (18-8) allowed two runs on seven hits with two walks and seven strikeouts, while also posting an RBI single in the rout. The NL leader in wins recorded his third straight victory with the effort.
"I'd trade all of those wins in a heartbeat for a shot at the playoffs," Zimmermann said.
Roger Bernadina doubled twice and scored once for the Phillies, who lost for only the third time in their last nine, with Kevin Frandsen and Chase Utley knocking in a run each
Tyler Cloyd (2-5) was torched for 10 hits and five runs over four-plus frames.
Back-to-back doubles from Harper and Desmond in the bottom of the fourth tied the game at 2-2, then a one-out hit from Ramos brought in Desmond to put the Nationals ahead. Steve Lombardozzi then singled but was tagged out trying to stretch it, leaving Ramos at third. He scored when Zimmermann aided his own cause with a base hit for a 4-2 game.
Ryan Zimmerman singled for Washington to start the bottom of the fifth, moved up on a wild pitch and scored on a Jayson Werth single as Cloyd was pulled for J.C. Ramirez, who set down the next three batters.
"He has to be real good with his command, and it seemed like today that balls started to be elevated a little bit and caught a lot of the plate," Phils manager Ryne Sandberg said of his starter. "Against that lineup, and the way they're swinging the bat, it's a tough combination."
Ramos' blast to center which began the home sixth boosted Washington to a 6-2 edge. A pair of two-run singles from Desmond and Ramos in the seventh brought the advantage to 10-2, and Denard Span's two-out RBI hit later in the frame accounted for the final margin.
The Phils picked up a run in the second, as Domonic Brown led off with a double, went to third on Cody Asche's infield hit and scored on a Frandsen fly to left.
In the home half, Harper led off with a double and later scored on a two-out single from Ramos.
Bernadina kept the leadoff double theme going in the third, moved up on a groundout and scored on an Utley grounder for a 2-1 Philadelphia lead.