Washington Nationals fans took back their ballpark from the invading fans of the Philadelphia Phillies on Friday night. And they did it by a landslide, not by some piddling plurality.

Then the Nats themselves, cheered on by a roaring crowd of 34,377, came from behind to beat Philadelphia, 4-3, in the bottom of the 11th inning, igniting an explosion of cheers and a throng of celebrating Nats surrounding pinch hitter Wilson Ramos near first base. As the last available healthy player on the Washington bench, Ramos knocked home the winning run with a bases-loaded single off Michael Schwimer to end a 3-hour 42-minute tingler.

The final run came out of nowhere, started by a two-out single by rookie Steve Lombardozzi for his third hit of the night. Six far more promising Nats rallies had already failed. But this time Bryce Harper drew his third walk of the game and Jayson Werth, after an awful 0-for-5 night, worked a full-count walk to bring up Ramos for his liner over the shortstop’s head.

As the Nats walked, or rather danced, off the field, an exact accounting of the true state of the crowd became apparent. Perhaps one in five fans trudged toward the exits in Phils gear. The remaining huge preponderance stood and cheered. And cheered as the PA pumped the moldy KC and the Sunshine Band chestnut “Get Down Tonight.”

All of this, accompanied by the early-season chills of the Nats’ MLB-leading fifth walk-off win of the season, raises a question as these teams prepare to meet twice more this weekend. The Nats have proved they can Take Back The Park. After this win, even more supporters may find their way out of the woodwork. Here’s the tough one: When, or will, the injured, stumbling 13-14 Phillies be able to Take Back First Place in the National League East from the team that now holds it? That would be the 17-9 Nats.

“Very refreshing,” Ian Desmond said of the crowd while Danny Espinosa added: “It’s awesome to have our own fans here. But there’s still definitely a vocal minority.” That includes a contingent by the right field bullpen that heckles Werth and likes to scream at Stephen Strasburg, as he warms up: “You’re going to blow out your shoulder.”

“You can still hear them, but it’s much different now,” said Strasburg, who allowed three runs in six innings and hit a double but left with a 3-2 deficit. He was saved from a defeat by a two-out, game-tying double by Jesus Flores in the eighth.

The Nats were acutely aware that the team’s marketing slogan, while ultimately helpful, also had the potential to backfire. “We almost had to win tonight,” said reliever Drew Storen, reduced to bench jockeying while still on the disabled list. “You get that turnout after kind of a controversial marketing campaign, you have to play to back it up.”

Baseball never ceases to obliterate our expectations. Washington fans come up big, but Strasburg gets knocked around and has to be saved from a defeat: You could’ve won my car and one of my family dogs on that parlay.

Nats fans dominated, both cheering and booing more loudly. Quick, get me oxygen, cheesesteak breath. Who knew the combo of hokey marketing and hometown pride still worked so well?