In the opener, Jenrry Mejia pitched seven scoreless innings in his season debut and Daniel Murphy homered twice and tied a career high with five RBIs as Mets won 11-0. Murphy had two hits for New York in the nightcap and went 6 for 9 in the day-night doubleheader.
After Anthony Rendon grounded out, Zimmerman hit a 3-1 fastball from reliever LaTroy Hawkins (3-2) over the fence in right center. The Mets wasted another impressive outing by Matt Harvey, who gave up five hits and an unearned run in eight innings.
Rafael Soriano (2-2) pitched the ninth, surviving a first and third jam with one out.
Jayson Werth added three hits for Washington.
Pitching on the one-year anniversary his major league debut, Harvey struck out seven and walked one.
Washington starter Ross Ohlendorf, making his second start of the season, went seven innings. He allowed one run on six hits while striking out eight and walking two.
The Nationals tied it in the fifth. Werth led off with a single and Ian Desmond walked. After Harvey fanned Steve Lombardozzi, Wilson Ramos hit a grounder up the middle. Turner fielded the ball behind second and shoveled it with his glove to Murphy.
Murphy barehanded it for the force and turned and threw to first, but his throw was wide and hit Ramos, allowing Werth to score on the error as the ball rolled into the infield.
Mejia (1-0), who had been on the disabled list since March with shoulder inflammation, allowed seven hits. He struck out seven with no walks.
"I haven't seen him obviously that good in a long time," manager Terry Collins said, adding Mejia will remain with the Mets. "The command of his stuff was very, very good. His location. I thought he pitched an outstanding game."
Mejia, 23, was 0-4 for the Mets in 2010. He underwent Tommy John surgery in 2011 and spent most of 2012 at Triple-A Buffalo. He was 1-2 with a 6.33 ERA in three September starts for the Mets.
Prior to being recalled for Friday's start, the right-hander went 2-0 in a pair of rehab starts at Double-A Binghamton.
Steve Lombardozzi and Zimmerman had two hits apiece for Washington.
Jordan Zimmermann (12-6), who allowed seven runs in a career-low two innings Sunday in a 9-2 loss to the Dodgers, needed 118 pitches to go 6 2-3 innings. He allowed five earned runs and six hits in picking up his third straight loss.
With one out in the first, Murphy hit a 1-1 slider off the second deck facade in right-center to make it 1-0.
In the third, after Lagares doubled with two outs, Murphy put New York up 3-0 when he lined a pitch into the Nationals bullpen for his eighth homer.
Murphy has hit safely in 16 of his past 17 games.
After Washington's Bryce Harper singled in the eighth, he was removed for pinch-runner Scott Hairston and was not in the lineup for the second game. Johnson said Harper aggravated his left knee diving for a ball.
Harper pinch hit in the second game and grounded out against Harvey.
- Mets LF Andrew Brown and SS Justin Turner collided and appeared to bump heads while chasing a popup in the first inning of Game 2. Turner made the catch and remained down as the Mets' trainer came out. Turner and Brown remained in the game, but Turner left in the seventh with a sore right shoulder.
- LF Eric Young Jr. was scratched from the Mets game one lineup after a pregame workout to test his right knee. He injured the knee Wednesday on the play in which Tim Hudson fractured his right ankle and left Thursday's game against Atlanta in the fourth inning.
- Washington activated RHP Ryan Mattheus from the disabled list. The reliever missed 58 games with a fractured right hand.. New York's Dillon Gee (7-7, 4.07) opposes Dan Haren (4-11, 5.79) Saturday.