On a day when the Orioles had two players leave the game injured, they also scored just two runs in a 4-2 loss to the Nationals in front of 36,614 at Nats Park.
The Nationals scored three times in the last of the sixth to break a 1-1 tie. Michael Morse hit a two-run homer off Matusz to right field to make it a 3-1 game. It was his 12th homer in his last 38 games.
Not long after Clay Rapada replaced Matusz, Ivan Rodriguez came up with an RBI double for a 4-1 edge. J.J. Hardy's RBI single in the top of the seventh cut the Nats lead to 4-2, but Henry Rodriguez got Nick Markakis and Adam Jones out to strand two runners.
Matusz took the loss to fall to 1-2 with an ERA of 5.60 in four starts since coming off the disabled list. Jordan Zimmerman gave up two runs over 6 1/3 to get the win and is now 5-6 with a 3.08 ERA. Drew Storen pitched the ninth to record his 17th save.
Matusz is now 0-3 with an ERA of 4.91 in four career interleague starts.
Derrek Lee went 2-for-4 with a double and is now 7-for-9 in this series. Jones hit a solo homer in the first inning. It was his 10th of the season and his fourth in 15 games in June.
The Orioles fall to 1-4 on their nine-game road trip and 31-37 on the season. They have lost six of their last seven games. They had won five of the last six against the Nats until this weekend but now will need to win Sunday to avoid a sweep.
The Nationals pulled to within a game of .500 at 35-36 with their eighth straight win. The Nats take a 3-2 lead on the Orioles in the season series but the O's lead the all-time series 18-17.
In Sunday's series finale at 1:35 p.m. Chris Jakubauskas (1-0, 5.09) is scheduled to pitch against lefty Tom Gorzelanny (2-4, 4.25).