Pinch-hitter Kory Casto doubled in the tiebreaking run in the seventh inning and scored on a single by Elijah Dukes to carry the Nationals to their second straight win following a four-game skid. The game attracted a crowd of 35,830 - the largest at the $611 million stadium since opening night.

Adam Jones went 3-for-3 with a walk for the Orioles, who fell to 10-6 in interleague play.

With the score 2-all, Willie Harris led off the seventh for Washington with a walk off Daniel Cabrera (5-4). Casto followed with a double to left, and one out later Dukes hit an RBI single.

Cabrera, who allowed four runs and nine hits in 6 1-3 innings, is 0-3 in seven starts since May 20.

Joel Hanrahan (4-2) pitched a scoreless seventh inning and Jon Rauch, the fifth Washington pitcher, got three outs for his 16th save in 20 tries.

Brian Roberts led off the ninth with a double and Nick Markakis walked, but Melvin Mora hit into a double play before Kevin Millar flied out to center.

And then, the crowd stood and cheered as fireworks soared into the sky.

Working on a limited pitch count after missing 3 1/2 weeks with shoulder tendinitis, Nationals starter Odalis Perez gave up three hits and three walks in four innings. He left with a 2-0 lead, but the Orioles pulled even against reliever Steven Shell.

Roberts opened the fifth with a triple and scored on a groundout by Markakis. The hit extended Roberts' hitting streak to 14 games, six short of his career high.

Baltimore tied it with an unearned run in the sixth. Jones singled and took second when left fielder Wily Mo Pena misplayed the ball. Brandon Fahey, called up from Triple-A Norfolk earlier in the day, followed with a bloop single that scored Jones.

Fahey was out trying for second, however, and the Orioles got only two more hits the rest of the way.

Washington took a 2-0 first-inning lead on RBI singles by Lastings Milledge and Jesus Flores. Cabrera allowed hits to four of the first five batters before Aaron Boone hit into an inning-ending double play.

In the second, Milledge hit a routine fly to right after the Nationals loaded the bases with two outs. That started a run in which Cabrera retired 13 of 14, including the last 11 leading up to the pivotal seventh inning.

Baltimore got runners on second and third with two outs in the fourth, but with Cabrera coming to the plate, the uprising was as good as done. Cabrera struck out, giving him 13 strikeouts in 13 career at-bats.

He made it 14-for-14 in the sixth.

Notes

Baltimore has been outscored 57-34 in the first inning. ... With Perez getting a no-decision, Nationals starters have two wins in Washington's last 27 games. ... The start of the game was delayed 13 minutes by rain.