Orioles 4, Nationals 3: Steve Pearce homered and scored a pair of runs as host Baltimore posted its eighth win in 10 games.Adam Jones and Nelson Cruz each added an RBI for the Orioles, who took two of three in the rain-shortened interleague home-and-home series. Wei-Yin Chen (9-3) allowed three runs and eight hits over 5 2/3 innings and Zach Britton worked around a hit in the ninth for his 15th save.Jayson Werth belted a solo homer while Ryan Zimmerman and Ian Desmond also drove in one run apiece for the Nationals, who lost for just the third time in 11 contests. Gio Gonzalez (6-5) yielded four runs - three earned - in 6 2/3 frames as both his three-start winning streak and 22-inning scoreless stretch came to an end.Pearce gave Baltimore an early lead, lining a 2-0 fastball from Gonzalez out to left for a one-out solo shot in the first inning. He also was an integral part of the Orioles' two-out, three-run rally in the third as he followed a walk to Nick Markakis with a single before Jones delivered an RBI double.Cruz plated Pearce with an infield single and Jones came around to score when Washington shortstop Desmond made an ill-advised throw to third on the play that was well off the mark. The Nationals chipped away as Zimmerman stroked an RBI single in the fourth before Werth led off the sixth with a blast and Desmond ripped a run-scoring double later in the frame to chase Chen, but were unable to complete the comeback.GAME NOTEBOOK: Cruz's third-inning single was his first hit in 12 career at-bats against Gonzalez. ... Baltimore RHP Darren O'Day created a jam in the eighth inning but managed to escape, loading the bases on a double, an intentional walk and a hit batsman before inducing a flyout by Wilson Ramos to end the threat. ... Nationals LF Bryce Harper was hitless in three at-bats, falling to 1-for-20 in his last six contests. ... Desmond exited in the eighth inning with a thumb injury suffered when he was hit by a pitch.