Baltimore, MD -- (Sports Network) - John Lannan pitched 7 1/3 strong innings, and the Washington Nationals edged the Baltimore Orioles, 2-1, to salvage one win from this three-game interleague set.

Cristian Guzman went 2-for-3 and hit a solo homer for the Nationals, who avoided a three-game sweep in the Battle of the Beltways. Lannan (4-4) scattered four hits and allowed one run, fanning five and walking one.

"He was tremendous, he was Madduxesqe," Nationals manager Manny Acta said of his starter. "He kept it down and in the glove the whole day. He was getting quick outs, the kid deserves all the credit."

Jon Rauch tossed the scoreless ninth for his 10th save, wrapping up the water- logged win for the Nationals, who had won three of four from the Mets before coming to Baltimore.

The game was delayed a total of two hours and 28 minutes by rain, including just over two hours before the first pitch was thrown.

Jeremy Guthrie (2-4) was the hard-luck loser, giving up only five hits and one run in seven innings for the Orioles, who had won four straight. A Brian Roberts sacrifice fly in the eighth accounted for the lone Baltimore run.

Guzman got the Nats on the board with his fourth homer of the season, pulling a fastball on the outer half of the plate out to right-center with two outs and nobody on in the third, and Washington took a 1-0 lead.

Elijah Dukes tried to double the Nats lead in the seventh when Wil Nieves singled to right with two outs. Dukes tried to score from second, but Nick Markakis threw a strike from right, gunning Dukes out at the plate to end the frame.

Felipe Lopez laced a leadoff double in the eighth. After Guzman bunted Lopez over to third, Ryan Zimmerman ripped a double to right, and the Nats took a 2-0 lead.

The Orioles finally broke through after another rain delay in the eighth. Adam Jones singled to center to lead things off, and Luke Scott hit a one-out double to right, putting runners at second and third with one out. A pitching change was then followed by a 27-minute rain delay, and when the game resumed, Luis Ayala was facing Roberts. Roberts lofted a sacrifice fly to center, plating Jones, but Melvin Mora lined out to right, ending the threat with the Nats still on top.

Rauch worked around a two-out single by Aubrey Huff, and nailed down the win for Washington.

Game Notes:

The Nationals left eight runners on base...Washington hosts Philadelphia on Monday, while the Orioles travel to New York, taking a day off before playing the Yankees on Tuesday...Attendance was 33,745.