His shirt already soaked through, Ryan Zimmerman grabbed a bottle of Dom Perignon 2002 and plodded forward on the squishy carpet of the Washington Nationals clubhouse. Behind him, teammates pushed Wilson Ramos in a laundry cart. Gio Gonzalez grabbed Jordan Zimmermann’s face and screamed. Sean Burnett fell on the floor, rolling with laughter. Suds pooled on coolers. “Where’s Davey?” Zimmerman asked, cutting through the scene, looking for his 69-year-old manager.

They had reached this point together, from the sun-splashed February diamonds in Viera, Fla., through the sweltering summer months to Monday night, when the simple, feverish roar from 35,387 souls at Nationals Park let them know: At 9:45 p.m., when the Atlanta Braves suffered a 2-1 defeat in Pittsburgh. In minutes, their 2-0 loss to the Philadelphia Phillies would become moot. They were the champions of the National League East, set to begin a five-game NL Division Series either Saturday or Sunday.

That they had clinched on a loss could not stifle the cheers or quell the party. And why should it have?

“We won 96 games,” owner Theodore N. Lerner said, standing on the infield grass in a quieting stadium. “So we’ll take it.”

In the middle of the ninth inning, Manager Davey Johnson climbed the steps of the dugout and waved to the crowd. The lights of the Capitol Dome glowed in the distance. The city, with three meaningless outs to go, had witnessed its first clinching of first place since the Washington Senators won the pennant in 1933.

No one could quite point their finger to when it hit them. But during a season sprinkled with pixie dust they all reached the same conclusion.

“The boys thought we were the team to beat,” first baseman Adam LaRoche said.

The Nationals had lost the clincher, but they had earned their way to the top of the division. They gathered in spring training as an upstart separating themselves from a dismal past. They sprinted out of the gate. They weathered injuries that would have obliterated their season if not for minor league reinforcements, particularly their 19-year-old shock of energy. They emerged in late summer as the best team in the major leagues, good enough to lose nine of 17 games and preserve their first division title.

“We put ourselves in that position,” said Zimmerman, the franchise third baseman who signed a $100 million contract to play here the rest of his career. “We made these other teams play perfect baseball to catch us. The way we played all year is really what got us in this position.”

The Nationals snatched the crown off the collective head of the Phillies, who had celebrated three of their five consecutive division titles — 2007, ’08 and ’10 — with victories over Washington. This year, the Phillies will watch the playoffs from home, and Monday night they had to watch the Nationals slip on T-shirts and hats, even after a win.

“That’s the first time I ever won and got beat,” Phillies Manager Charlie Manuel said.

After the final out, the players lingered on the steps of the dugout and received the hats and T-shirts before retreating to their clubhouse. The Nationals had shipped their unopened champagne, Korbel and a few bottles of higher-shelf stuff, back from St. Louis. “There’s enough,” clubhouse manager Mike Wallace said before the game, smiling.

Players popped the champagne and soaked each other. They circled Mike Rizzo, the general manager who drafted Stephen Strasburg and Bryce Harper and overhauled the baseball operations department.

“It was amazing,” Rizzo said. “The camaraderie of the guys. We were soaked together. As a group, they know where we all came from.”

In another corner of the clubhouse, Harper stood with LaRoche’s 9-year-old son, Drake. They were the only underage participants, and so they shared a bottle of apple cider. “Me and Drake were pouring that on top of each other,” Harper said.

Harper joined the Nationals in Los Angeles in late April, both a needed left-hander for practical purposes and also a metaphorical embodiment of the Nationals’ arrival.

“I didn’t want to come here and screw things up,” Harper said. “We were already in first place.”

For the next five months, fighting and conquering slumps, Harper energized his awestruck veteran teammates. He clobbered baseballs like few 19-year-olds in history, patrolled center field with powerful grace and ran the bases like a freight train.

“I’m just so happy to be here at this moment, with these guys, this team,” Harper said. “Being able to enjoy this is the best experience I’ve ever been apart of.”

When the Nationals brought Harper to the majors, they said it may be a temporary arrangement. It private, they knew better. “We kind of saw this guy being a big part of this team,” Rizzo said. “I’ve been scouting a long time, and it’s not so tough to say he’s different than the rest of us.”

Harper had started the year in Class AAA Syracuse with John Lannan, twice the Nationals’ opening day starter, exiled to the minors because of the team’s influx of power arms. They handed Lannan the ball Monday night, back in the rotation. They couldn’t recover from the two runs he allowed in the second inning, but he soaked in the moment.

“It’s unbelievable,” Lannan said. “I never really thought much about what was going on when I was down there. I never really knew why it was happening. Now it’s kind of all making sense.”

In the ninth inning, after the Braves had lost, Jayson Werth looked across the diamond at his old manager, Manuel. He nodded as a way to say thanks. Werth had come to Washington last year on a seven-year, $126 million contract, trading first place for last. He had a vision, and it came to life sooner than he expected.

“It’s gratifying,” Werth said. “It’s quite an accomplishment. We’ve come a long way in a short time. We’ve got a young club. I think we should do this every year.”

In the late afternoon, as the Nationals took batting practice, Mark Lerner greeted players and hobbled around the cage with a cane. He still wore a cast on his lower leg and foot as he recovers from a late-summer operation. “A little champagne will cure it, I’ll tell you that,” Lerner said.

Later, after the dawning of a new era in Washington baseball, Lerner celebrated with his father. “It was fortunate to draft Steve Strasburg. And then Harper,” Theodore Lerner said. “Building an organization. Building a scouting system. Building a player development system. And then hoping it will all come together eventually. We never knew when it would occur. It came together a little earlier than we expected.”