Washington, DC (Sports Network) - Kory Casto and Elijah Dukes both stroked RBI hits in the seventh to lift the Washington Nationals to a 4-2 decision over the Baltimore Orioles, in the opener of a three-game 'Battle of the Beltway' interleague set at Nationals Park.

Adam Jones was 3-for-3 with a run scored and Brian Roberts tripled, doubled and scored a run. Nick Markakis and Brandon Fahey recorded an RBI each for Baltimore, which has dropped two of three.

Daniel Cabrera (5-4) retired 11 straight down the stretch but took the loss after running into trouble in the seventh. The righthander finished going 6 1/3 innings, allowing four runs on nine hits and three walks while fanning four, remaining winless since May 20.

"After the first inning, he pitched down," O's skipper Dave Trembley said of his starter Cabrera. "He ran the ball in on some right-handed hitters. He was better. He was a lot better."

Lastings Milledge was 2-for-4 with a run scored and an RBI while Dukes, Casto and Jesus Flores all has RBI hits for Washington, which has taken two straight following a four-game skid.

Odalis Perez, activated from the disabled list on Thursday, went just four innings but kept the O's off the scoreboard on three hits and three walks. Perez tossed 75 pitches in the outing and struck out three after being sidelined since early June with shoulder tendinitis. Joel Hanrahan (4-2) recorded the win with a scoreless seventh.

Washington regained the lead in the seventh. Willie Harris walked to start the frame and pinch-hitter Casto ripped a double to left scoring Harris. Casto moved to third on a wild pitch and scored when Dukes singled back through the middle two batters later. After a Milledge single, Cabrera was lifted in favor of Dennis Sarfate, who recorded two of the next three batters to end the inning without incident.

"Coming off the bench, it's tough," Casto said of his role. "I've never really done it. I'm starting to feel a little more comfortable whether I'm starting or not."

Jon Rauch came on to close the door in the ninth and allowed a leadoff double to Roberts followed by a walk to Markakis. Rauch then induced Melvin Mora into a 6-4-3 double play and retired Kevin Millar on a fly out to end the game and record his 16th save of the season.

Washington posted a pair of runs in the first. Cristian Guzman doubled to right-center leading off and scored on a Milledge single back up the middle. Milledge advanced to third when center fielder Jones mishandled the ground ball and scored when Flores lined a single to right.

Baltimore pushed a run across in the fifth and sixth innings off Steven Shell to tie the game at two. Roberts led off the fifth with a triple to right and scored on a Markakis groundout. Jones led of the sixth with a single to left and took second when Wily Mo Pena bobbled the ball. Fahey then plated Jones with a single to left but was thrown out by Pena trying to advance to second.