PHILADELPHIA -- Despite the struggles of one of their star pitchers, the Washington Nationals are playing front-runners in the National League East.

If Stephen Strasburg is back to full form, the rest of the division -- and the league -- could be in some serious trouble.

Strasburg, a 26-year-old former All-Star, had one of his best outings of the season on Sunday, going seven strong innings as the Nationals beat the Philadelphia Phillies 3-2 in the first game of a doubleheader.

With the win, Strasburg improved to 2-0 since his return from the disabled list on June 23. After starting off the year 3-5 with a 6.55 ERA before neck and back problems sent him to the disabled list in late May, he has only given up two runs in 12 innings to improve to 5-5 with a 5.49 ERA.

The Nationals (42-33) got behind 1-0 early on a home run by Phillies right fielder Jeff Francoeur, but evened things up in the fifth. Third baseman Danny Espinosa's sacrifice fly with one out scored center fielder Denard Span, who had reached third base after Francoeur was unable to cleanly handle his double into the right-field corner.

The Nationals took the lead an inning later thanks to left fielder Michael Taylor (2-for-4, RBI), whose double off Phillies starter Kevin Correia (0-2, 3.60 ERA) scored first baseman Clint Robinson and chased Correia from the ballgame. It became 3-1 when Phillies catcher Cameron Rupp allowed a passed ball, with Dan Uggla, who was 3-for-4, scoring from third base on the error.

Correia gave up seven hits and three runs (one earned) in 5 1/3 innings of work, walking three and striking out four.

The Phillies (26-50) got one back in the bottom of the sixth on an RBI single from Francoeur, who was 2-for-4 with two RBIs, but only managed one more hit the rest of the way.

Washington closer Drew Storen got one out in the eighth and pitched a perfect ninth for his 23rd save of the season.

NOTES: The Phillies and Nationals managed to play 1 1/2 innings of Saturday's game before it was canceled due to rain. Sunday's game, originally scheduled to start at 1:35 p.m. ET, was moved up to 1:05 p.m. and became the first of a single-admission doubleheader, the first true doubleheader in Philadelphia since Sept. 3, 2006. ... Both starting pitchers, Strasburg (West Hills HS) and Correia (Grossmont HS) are San Diego natives, though Correia is eight years older than his counterpart. . . .Entering play on Sunday, Nationals starters have only given up one run in their previous 48 innings of work. A streak of 47 1/3 scoreless innings was ended on Friday night in a 5-2 Washington win. ... Phillies starters are 1-14 with a 6.41 ERA in June, both the fewest wins and highest ERA of any starting staff in the majors over that time.