WASHINGTON (AP) David Wright raced around the bases, slid home ahead of Wilson Ramos' tag, made the ''safe'' sign toward the umpire and pumped his fist in celebration.
The New York Mets had broken away in a game their manager called the biggest of the season.
Yoenis Cespedes homered and doubled twice, Wright hit a go-ahead single and scored to cap a three-run seventh inning, and the Mets ended Washington's five-game winning streak, beating the Nationals 8-5 Monday to open a key NL East series.
''Throughout the last couple years, that emotion hasn't quite been there,'' said Wright, the team captain who spent most of this season on the disabled list. ''You miss that emotion and that passion, and you get a chance to play in a game like this, that's a lot of fun.''
Michael Conforto and Kelly Johnson also homered and Curtis Granderson doubled twice for the Mets, who increased their division lead to five games over the Nats with 25 remaining. New York last made the postseason in 2006.
Washington star Bryce Harper wasn't happy with some Nationals fans who exited early.
''They left in the seventh, that's pretty brutal,'' Harper said. ''Playoffs is totally different. Our fans are going crazy.''
After losing two of three at Miami over the weekend while speculation swirled around a potential innings limit for starter Matt Harvey, New York's lead could've dwindled to three games after it was 6 1-2 on Sept. 2.
''They came out today, in the biggest game I think of our entire season thus far, fall behind and then came back and held on,'' Mets manager Terry Collins said. ''It was a great win.''
Dario Alvarez (1-0), pitching in the majors for the first time this season, faced only one batter - Harper - and struck him out to get his first major league win.
Five Mets relievers combined for 5 2-3 scoreless innings. Jeurys Familia struck out the side for his 37th save, including Harper.
Wilson Ramos hit a grand slam for Washington, the second of his career, off Jonathon Niese, who gave up five runs in 3 1-3 innings.
Nationals ace Max Scherzer allowed five runs over six innings on seven hits - three homers and four doubles. He's been tagged for 11 home runs in his last six starts, and exited with a season-high 3.03 ERA.
Scherzer also grounded out to end the bottom of the fifth after manager Matt Williams let him bat with runners on second and third.
''He's got pitches left,'' Williams said of the decision. ''He's at 90 and he's got the lead. He's our No. 1 for a reason.''
Cespedes hit his 31st home run this season, and 13th in 34 games since being traded from Detroit to the Mets, to help build an early 3-0 lead. His three extra-base hit game was his third this season since the trade, tying a Mets season record.
''There's a reason why we went and got him, and there's a reason why we traded what we traded to get him,'' Collins said.
The Nationals scored five times in the fourth to take a 5-3 lead, and it was tied when Blake Treinen (2-3) took over for Scherzer to begin the seventh. The Mets wound up scoring three times against four Washington relievers.
Wilmer Flores led off with a single, Granderson drew a walk from Felipe Rivero and Wright hit an RBI single. Daniel Murphy had a sacrifice fly and Wright raced home from first on Cespedes' double to right-center, sliding in just ahead of Anthony Rendon's relay throw.
''I felt like I was probably going a lot faster than I really was, and just trying to pick them up and put them down,'' Wright said. ''But, again, you get the adrenaline pumping and just, what a game, just what a game.''
POINT TO PROVE?
Collins said he believes Harvey will have a strong performance in Tuesday's start against Washington, with debate swirling on a potential innings limit that could limit his postseason availability.
''I think Matt Harvey's going to step up and show everybody in New York, everybody in baseball, that he's as tough as the persona he puts on,'' Collins said.
Mets: Activated 1B Lucas Duda (back stiffness) from the disabled list before the game. He wasn't scheduled to arrive at Nationals Park in time to start. ... Collins said he doesn't expect a prolonged absence for LHP Steven Matz, who left with a blister in the sixth inning of Sunday's start against Miami. ... RHP Carlos Torres left in the fifth inning with a strained left calf.
Nationals: RHP Stephen Strasburg (back tightness) felt good after Sunday's bullpen session and will start Wednesday ''barring a setback,'' Williams said.
Mets: Harvey (12-7, 2.60) will make what could be one of his final starts of the regular season. In his first season after Tommy John surgery, Harvey has pitched 166 1-3 innings and could be shut down until the postseason at around 180, GM Sandy Alderson said Monday.
Nationals: RHP Jordan Zimmermann (12-8, 3.38) has allowed three or fewer earned runs in 23 career starts against the Mets, including five scoreless outings.