WASHINGTON -- Right-hander Jacob deGrom is not a bad hitting pitcher, as he posted an average of .214 last year while winning the National League Rookie of the Year with the New York Mets.

But Mets manager Terry Collins said there was a reason deGrom was moved from the infield to the pitcher's mound as a college player at Stetson in Florida.

Eric Campbell, as a pinch-hitter in the seventh for deGrom, lined a two-run single with one out to key the Mets past the Washington Nationals 7-2 on Tuesday in a National League East showdown.

Campbell's first hit in eight pinch-hit at-bats this season drove in the tying and go-ahead run.

"It ended up working out for the best," said deGrom, with a smile. "He did a great job. It was a good team win."

"He put a good swing on it. I thought this was the spot for Eric," Collins said of Campbell, who was robbed of extra bases and two RBIs the previous night on a great catch by Michael A. Taylor in center field. "It was a big win for us. We rolled the dice" with Campbell hitting for deGrom.

The Mets tacked on four in the ninth on RBI singles by right fielder Curtis Granderson (two hits), shortstop Ruben Tejada and third baseman Daniel Murphy against reliever Tanner Roark. Second baseman Wilmer Flores, who had two hits and two RBIs, drove in the fourth run of the inning with a groundout.

The second-place Mets (49-45) pulled to within two games of first-place Washington (50-42), which won the previous three games against New York this season.

The deciding game of the three-game series will be Wednesday afternoon.

DeGrom (10-6) allowed two runs on three hits with eight strikeouts and no walks in six innings. In his last four starts, deGrom has given up just five runs.

In the All-Star game last week, deGrom struck out three batters on 10 pitches. He said he was pumped to face the first-place Nationals.

"I would say I was little amped up tonight to get out there," deGrom said.

"He gets a lot of chase on sliders off the plate," Washington manager Matt Williams said of deGrom.

Collins realized deGrom could have gone deeper in the game but felt he had to pinch-hit him for with the Mets trailing.

"He pitched a great game," Collins said.

Jenrry Mejia threw a scoreless seventh for the Mets, Bobby Parnell pitched a perfect eighth and Jeurys Familia tossed the ninth.

Joe Ross (2-2), the Washington starter, gave up four hits and three runs (two earned) in 6 1/3 innings in his fourth big league start.

"I felt good. I wanted to stay in and try to pitch out of it," Ross said of Aaron Barrett coming on in the seventh. "Barrett was probably the smart move."

Ross made three starts earlier in the year then was sent to Triple-A Syracuse, where he made five starts before being called back up to Washington.

"It has been good. I have tried to stay focused," Ross said of his time with Syracuse after beginning the year with Double-A Harrisburg.

The Mets are just 17-31 on the road this season but 24-16 against National League East foes.

Ross retired the first nine batters before Granderson led off the fourth with a ground single.

Granderson then stole second with no outs and scored on a solid two-out single to center by Flores to give the Mets a 1-0 lead. Ross escaped a big inning when he got left fielder Kirk Nieuwenhuis to line out to short for the final out of the frame.

But the Nationals grabbed a 2-1 lead in the fifth on a two-run homer by catcher Wilson Ramos off deGrom. It was the first homer since July 5 for Ramos, who was hitless in his previous eight at-bats and was hitting just .161 in the last 15 games.

NOTES: RHP Abel de Los Santos made his MLB debut in the ninth out of the bullpen. He pitched 2/3 of an inning, giving up zero runs. ... Mets RHP Noah Syndergaard (4-5, 3.05 ERA) will face Nationals RHP Jordan Zimmermann (8-5, 3.27) in the series finale Wednesday afternoon. ... To make room for RHP Joe Ross on the 25-man roster, the Nationals sent INF Wilmer Difo to Double-A Harrisburg. ... Nationals OF Matt den Dekker was acquired from the Mets in a March 30 trade reliever Jerry Blevins, who has been on the disabled list since April 21 with a broken left arm.