Washington, DC (Sports Network) - Jose Bautista ripped a pair of home runs and finished with four runs batted in, and the Pittsburgh Pirates blasted Washington, 11-4, at Nationals Park.

Ryan Doumit finished 3-for-5 with two RBI, while Nate McLouth, Jason Bay, and Chris Gomez each had a pair of hits for the Pirates, who have won two of three.

Starter Phil Dumatrait only lasted four innings after giving up four runs on six hits, but four Pittsburgh relievers combined to throw five scoreless innings the rest of the way. Damaso Marte (2-0) threw two perfect innings in relief to pick up the win.

Nationals starter John Lannan (2-3) had a scoreless streak of 21 innings come to an end, and he finished the night after just three innings of work, in which he threw 85 pitches and allowed six runs -- five earned -- on six hits and two walks.

Felipe Lopez went 2-for-4 with a double and RBI, while Wil Nieves hit a two- RBI double for Washington, which had a four-game win streak snapped. Catcher Paul Lo Duca was reinstated from the 15-day disabled list earlier Friday, and singled in a pinch-hit appearance.

Lannan's scoreless streak ended in a burst in the third. McLouth led off with a double and after Sanchez grounded out, Bay walked. Doumit then singled to plate McLouth and put runners on the corners.

Xavier Nady followed with his own single, to replicate the play -- Bay scored, and runners were left on the corners. Doug Mientkiewicz then hit a grounder to drive in Doumit for a 3-0 Pirates lead, but Lopez didn't handle Cristian Guzman's throw cleanly and both runners were safe.

Bautista capitalized on the gaffe by blasting the ball past the fence in left, boosting Pittsburgh's edge to 6-0.

"We thought we would correct a couple of things that would make him better and he's really stayed with it," Pittsburgh manager John Russell said. "He's swinging the bat much better every game and he had a big game for us tonight."

The Nationals cracked the scoreboard in the bottom half on a Lopez RBI double, but the Pirates got the run right back in the fourth as Doumit singled to plate McLouth.

Ryan Zimmerman led off the home fourth with a single, but the game was then delayed by a slight power outage -- a few sets of lights went out, and others dimmed. Play was halted for a little under half an hour, then resumed after the issue was resolved.

"I was very pleased with the way (Dumatrait) attacked the hitters, and kept the ball down," Russell said. "I thought he did a very nice job, it's just a shame the lights went out and we had that long delay."

Washington made it a productive inning, as Lastings Milledge doubled with one out, and Austin Kearns walked to load the bases.

A Wily Mo Pena sacrifice fly brought in Zimmerman, and Nieves doubled to left to clear the bases and bring the Nationals within 7-4.

However, Bautista again lofted a homer to left to give Pittsburgh a four-run cushion.

Pittsburgh added to its lead in the seventh, as a Gomez single plated two runs, and a final run in the eighth, when Bay doubled to right to drive in McLouth.

Michael O'Connor allowed four runs in 3 2/3 innings of relief for Washington, while John Grabow, Tyler Yates and Matt Capps each threw a scoreless inning of relief for Pittsburgh.