WASHINGTON -- Washington is wild.

The Nationals clinched a wild-card berth with a 6-5 win over old friend Bryce Harper and the division rival Philadelphia Phillies on Tuesday night. Technically, the spot wasn't locked up until three minutes after the last out. That's when the Chicago Cubs lost to the Pittsburgh Pirates, eliminating them from wild-card contention and sending Washington to the postseason.

The final out of the Cubs-Pirates contest was shown live on the giant video board at Nationals Park. As soon as Chicago slugger Kyle Schwarber grounded out to Pittsburgh's Adam Frazier to end it, the Nationals -- who had calmly congregated along the first-base line -- began their celebration in earnest, bouncing up and down as Panic! at the Disco's "Hey Look Ma, I Made It" blared throughout the stadium. It was a moment that, exactly four months ago, seemed improbable at best.

"I imagined it in spring training," said manager Davey Martinez, whose team was expected to be a World Series contender but went 19-31 over its first 50 games and had the third-worst record in the National League as of May 24.

Despite the slow start, Washington's second-year skipper remained his usual upbeat self.

"I said this team is going to bounce back and turn it around," Martinez said. "I thought we hit the bottom then, but this team -- we get everybody back, we get healthy, we're going to be OK. So let's just keep fighting, and here we are."

Although it's Martinez's first trip to the playoffs, it's the fifth time in eight years for the Nationals. Each of the previous four times, they were division winners. Not that anyone in Washington's clubhouse seemed to mind the team's wild-card status.

"Everybody in this clubhouse envisioned this exact thing right here," said shortstop Trea Turner, whose dramatic grand slam on Tuesday night was the decisive blow and resulted in a rousing curtain call from the surprisingly thin crowd of 22,214. "We talked about it when we were 19-31, we talked about how we were going to laugh at everybody else outside of this clubhouse for everything that they said about us, and we are here now."

"There's still a path for us to win it all," said ace Max Scherzer, who got the win Tuesday night and is expected to start the wild-card game next Tuesday. "We're going to get tested like we've never been tested during the regular season. But I love what this team has together. I love our chemistry. I love what we have. That's what it takes to win in the postseason."

Winning in the postseason is unfamiliar to the Nationals, who've never advanced past the first round in four tries under general manager Mike Rizzo.

"Each season is unique and special," said Rizzo, who joined the Nationals in 2007 and took over as GM two years later. "When you get to put plastic down and pour beer over each other, it's a special season. We don't take that for granted. These are things that a lot of teams wish they were doing."

One of those teams on the outside looking in is the Phillies, who had grand plans when they signed former Nationals star Harper to a 13-year, $330 million contract during the offseason, but were eliminated during the first game of Tuesday's doubleheader, a 4-1 loss. Their defeat in the nightcap, which came in spite of a pinch-hit homer from Harper, sent the former MVP's old club into celebration mode.

An impromptu conga line formed, propelling players around the clubhouse to the thumping beat of Latin music. Chants of M-V-P filled the Nats' locker room as teammates stood around third baseman Anthony Rendon and showered him with beer. Gerardo Parra led a rousing reprise of "Baby Shark," the toddler tune that the reserve outfielder adopted as his walk-up song earlier this season and has since become something of an anthem in the nation's capital.

"This is so awesome," said reliever Sean Doolittle. "After everything we've been through, coming together after everything over the course of the season and having to crawl out of the hole that we found ourselves in May, it makes it that much sweeter. This is really, really special."