It took five pitches.

Five pitches for the Mets to change the tenor of their season, for anxious excitement to turn into dizzy bedlam, and for this team to say loudly and emphatically that this is for real.

Five pitches for a one-run deficit to turn into an eventual 5-2 win over the Washington Nationals that created a virtual tie for first place in the NL East between the two teams.

The first pitch went to Curtis Granderson with two outs in the third inning. With Kevin Plawecki on second base and the Mets trailing by a run, he blasted a 2-and-2 curveball to right, a sky-high fly ball that landed somewhere below the Pepsi sign.

The crowd, a tense gathering that had mostly filed into Citi Field well before first pitch, exhaled. They screamed. They danced.

And they didn't much sit down after that.

The next pitch, Jordan Zimmermann's 96-mph fastball to Daniel Murphy, took the same trajectory. But after his drive high into the Pepsi Porch, the home run apple stayed down, unable to recuperate from Granderson's home run in the short time it took Murphy to go yard.

Yoenis Cespedes took a ball before stroking a single to left, his first hit as a Met. Then came Lucas Duda, who had hit eight home runs in seven games and promptly added to that streak on Zimmermann's first pitch.

It was the first time the Mets hit three homers in an inning since 2007 and the first time at Citi Field.

Duda's towering homer to rightfield gave the Mets a 5-1 lead and brought the type of raucous celebration usually reserved for postseason baseball.

No reason to calm down, though. Not even the Mets were downplaying the importance of the series and this particular game.

"I kinda hyped this up myself," manager Terry Collins said before the game. "We went out last week and we got ourselves three very good offensive players. They're playing tonight . . . I think this is a big game. I've got [Juan] Uribe in there, I've got Murph in there, I've got Kelly Johnson in there, Yo [Cespedes] is in there. We needed them, I'm playing them."

The Mets still are a bit behind the Nationals in winning percentage, .52427 to .52381. Still, by sweeping the Nationals in a three-game series for the first time since 2009, they are in a virtual tie for first place.

Despite giving up multiple home runs for the first time in his career, Noah Syndergaard (6-5, 2.66) proved reliable and was able to contain early jitters. Though he was not as dominant as he had been in his last outing, in which he pitched eight scoreless innings, he was able to work around home runs by Anthony Rendon and Yunel Escobar, giving up seven hits, walking none and striking out nine in eight innings (109 pitches).

With one out in the first, Rendon caught up to a belt-high, 98-mph fastball and blasted it to left-center. It originally was ruled a double, but a review showed it actually had hit above the orange line, giving Rendon his first home run of the season. Escobar homered to left-center to cut the Nationals' deficit lead to 5-2 in the sixth.

Former National Tyler Clippard replaced Syndergaard and pitched a scoreless ninth.