With 10 games to play, the Nationals have already exceeded last season's win total and have won seven of their last 10.
"As long as you're moving in the right direction, you're making progress," Washington reliever Tyler Clippard said. "That's what this organization has been doing the past three years. It's fun to be a part of it, and I think everyone is getting excited."
On Tuesday, the clubs will square off in a day-night doubleheader at Citizens Bank Park. Washington's Tom Milone will take the hill against Philadelphia's Kyle Kendrick in the first game. Philadelphia left-hander Cliff Lee will start the second game of the day against Nationals starter Ross Detwiler.
Milone, 24, has made three starts since being promoted from the Minors at the beginning of the month. He won his first Major League game in New York on Thursday, holding the Mets to one run on three hits in 5 2/3 innings. The left-hander struck out four.
The Phillies clinched their fifth straight division title on Saturday, but they aren't satisfied. A World Series championship still is the ultimate goal, and how they play the rest of the season will help toward achieving that title.
The Phils are coming off a 4-3 loss the Cardinals on Monday. They lost three of four games to St. Louis in the series and are trying to secure home-field advantage in the playoffs.
"I'm not really going to be satisfied until we win that last game," Philadelphia pitcher Roy Oswalt said. "I've done enough personal stuff that it really doesn't matter. All I want now is to win that last game. That's all any of us really want."
Phillies: Kendrick on a roll
In his last eight starts, Kendrick has a 2.60 ERA and could have a better record than 4-2. He threw just 78 pitches in his last start on Sept. 15, but was pulled because it was his first appearance since Aug. 24.
"Obviously, it's been a long time since I've thrown to a hitter or thrown in a game," Kendrick said after the start. "So they didn't want to risk injuries. That's fine."
Nationals: Mattheus hopes to pitch in '11
Reliever Ryan Mattheus, who has been on the disabled list since Aug. 26 with a sore right shoulder, is hoping to return before the season ends. He has a 2.40 ERA in 32 games this year.
"I want everybody to know that there are going to be no issues coming into Spring Training, and I'm going to be ready to go," Mattheus said.
The Phillies are 8-6 against the Nationals this season, including a 4-1 record in Philadelphia.
After Sunday's win, Nats closer Drew Storen was tied for fifth in the NL with 38 saves.