It was another night where the Orioles were shut down by a good pitcher and failed to score many runs or get key hits with runners in scoring position.
Edwin Jackson gave up just four hits and one run over 6 1/3 innings, as the Nationals beat the Orioles 3-1 in front of 46,298, the fifth sellout of the year at Camden Yards.
Jackson has given up just two runs over 14 1/3 innings this year in two starts against the Orioles, and he improves to 6-1 in his career versus Baltimore.
Meanwhile, for the second time this year, Wei-Yin Chen could not come up with a quality start against the Nats, as he gave up six hits and three runs (two earned) over five innings, throwing 90 pitches. Chen is now 7-3 with an ERA of 3.38.
He has lost both his starts against the Nationals, giving up 14 hits and eight earned runs over 9 1/3 innings in those games.
The Orioles were no-hit through 4 1/3 by Jackson until Wilson Betemit's single to left in the fifth, but they stranded the bases, which were loaded, that inning.
They got on the board when Adam Jones hit a line drive homer to left to start the last of the seventh. It was his 19th of the year and ended a nine-game homer and RBI drought for the O's center fielder.
The Orioles finished 0-for-3 with runners in scoring position, and they are just 1-for-27 with RISP over the last seven games. The Orioles have scored just 15 runs over their last eight games.
Betemit's throwing error in the second allowed one of the two Nats' runs to score that inning, as Washington took the lead for good. The Nats, now 41-28, added a run in the fourth on an Adam LaRoche solo homer.
The Orioles fall to 40-31 on the year, 20-15 at home and 3-2 against the Nats.
In the third and deciding game of this series, Sunday at 1:35 p.m., it will be Jake Arrieta (3-9, 5.83 ERA) for the Orioles and lefty Ross Detwiler (4-3, 3.34 ERA) for the Nationals.