With a new, energized fan base ready to burst, however, the Nationals went flat against the team they dethroned atop the National League East.
But everyone got to celebrate anyway.
Kyle Kendrick dominated the Nats, bulldogging his way through seven shutout innings and Darin Ruf hit a two-run triple in his first at-bat as the Phillies beat Washington, 2-0, for their third straight win. But Washington still clinched the franchise's first divisional title in 31 years when the Atlanta Braves also lost.
A half inning before Phillippe Aumont finished off the Nats, the Pittsburgh Pirates eked by the Braves with a 2-1 win that officially crowned Washington as the NL East champ.
The five-time defending NL East champion Phillies watched the division's newest top dog celebrate before taking the field for the bottom of the ninth.
"First time I ever won and got beat," manager Charlie Manuel said. "That's the beauty of the game, I guess . . . They did a good job. They deserved to win. They played the best."
The normally upbeat Manuel was downtrodden as reality sank in following the victory. But at the end of the disappointing season, some of his players could at least take solace in the fact that they didn't hand over an easy win to the Nats on Monday night.
Coming off his shortest start of the season a week ago, when he allowed five runs in two innings against the same Nationals team, Kendrick was nothing short of brilliant.
Through his first four innings, Kendrick held Washington to two singles. They were the only two balls to leave the infield.
In the fifth, with a runner on third, two outs and Jayson Werth at the plate with the ballpark abuzz, Kendrick struck out his former teammate looking. In the sixth, he completed the feat: After Bryce Harper led off with a double and advanced to third on a pop up to shallow right, Kendrick left him there by inducing an infield fly and striking out Michael Morse looking.
With each inning-ending out, the ballpark was temporarily silenced.
"That was the best atmosphere I've ever seen here," Kendrick said. "It was fun to pitch in that, for sure."
Kendrick capped his impressive final start of the 2012 season by striking out two of the three batters he faced in a 1-2-3 seventh. He held Washington to four hits while striking out four and walking one.
"Not letting them celebrate on the field was kind of nice," Kendrick said before Washington went ahead and celebrated anyway after the Phils' postgame handshakes on the infield. "They've obviously had a good year, but it was nice to end the season like that for me."
In a season that began in the bullpen and ended with him having locked up a rotation spot for 2013, Kendrick held opponents to two runs or less in 17 of 25 starts.
After allowing seven runs in three innings of his first start 6 months ago in Arizona, Kendrick went 10-10 with a 3.53 ERA in his final 24 starts.
"When I look at our team, yeah, definitely, he's in our rotation," Manuel said. "Unless we get [Tampa Bay ace David] Price or some other guy."
"His location has [improved]," Carlos Ruiz said of Kendrick's maturation in 2012. "Location was the key for him. The changeup was big for him. He was working down and had a very good [season]. He got a lot of ground balls, a lot of swinging misses. That's what he did in the game today.''
Although the Nationals officially overtook the Phils on Monday night, the former champs have won nine of the 16 games between the two teams this season. In his five starts against Washington this season, Kendrick went 2-2 with a 2.93 ERA.
With Washington boasting one of the best young pitching staffs in baseball, along with a lineup with rising stars and veterans alike, all under contract, the Phils will need more of the same from Kendrick in 2013. Not to mention the other 24 players in Phillies uniforms, too.
"We obviously have to get better," Kendrick said in a quiet, near-empty visiting clubhouse at Nationals Park. "They're young, they have a good rotation - they could be around for a while. But hopefully we get better. I think we have a chance of doing that."
But Manuel knows it won't be as simple as putting a pricey, veteran-laden roster on the field.
"We have to play much better," Manuel said. "We've got to play smarter. We have to know the game better. We have to play better defense. We have to have more knowledge for the game and what to do."
Contact Ryan Lawrence at firstname.lastname@example.org. Follow him on Twitter @RyanLawrence21.