Pittsburgh, PA (Sports Network) - Xavier Nady hit a two-run homer and the Pittsburgh Pirates defeated Barry Zito and the San Francisco Giants, 3-1, in the middle contest of a three-game series.

Phil Dumatrait (1-1) earned his first major league victory, tossing 5 2/3 scoreless innings, allowing three hits while striking out five and walking one.

Jason Bay added two hits, scored a run and walked for Pittsburgh, which will try for the series sweep on Thursday.

Zito (0-7) was effective despite taking the loss in his first start since being demoted to bullpen duty, although he hasn't had a relief appearance this season, and instead just missed a turn in the rotation. He mixed his pitches well with a healthy diet of breaking balls and change-ups. Through five innings, he surrendered two runs on five hits and two walks while striking out five.

"It's important to be aggressive every pitch," Zito said. "I would have liked to get ahead with more hitters than I did. I got ahead of 10 guys out of 21. Tip your cap to Nady, he hit a good pitch."

Randy Winn and Bengie Molina had two hits apiece for the Giants, who have lost three in a row. They've lost 14 of the last 17 versus Pittsburgh.

The Giants made things interesting in the ninth off Pirates closer Matt Capps, starting the frame with three straight singles from Winn, Aaron Rowand and Molina, whose hit scored Winn. However, Rich Aurilia flied out and Jose Castillo grounded into a double play to end the game, giving Capps his seventh save of the season.

Both starters escaped early inning jams without allowing any runs. Zito and Dumatrait both pitched out of first and third situations in the first and second innings, respectively.

Zito made one mistake in the fourth when Bay led off with a single and Nady drove a first-pitch change-up deep to left-center for his fifth home run of the season to make it 2-0.

Dumatrait settled down to retire 12 batters in a row until the top of the sixth when Dan Ortmeier pinch-hit for Zito and doubled to start the inning. Dumatrait then retired the next two before being replaced by Tyler Yates, who struck out Rowand.

The Pirates looked to add to their lead in the bottom of the frame off of new pitcher Keiichi Yabu with a leadoff walk from Bay followed by a wild pitch, moving him to second. Nady struck out swinging before Adam LaRoche singled Bay over to third. However, Yabu got Ronny Paulino to ground into a double play to end the inning and keep San Francisco close.

Yates stayed in the game to pitch the seventh and gave up a two-out double to Castillo, but turned around and got pinch-hitter Eugenio Velez to ground out.

Damaso Marte took over for Yates in the eighth and struck out the side.

Tyler Walker came on for the Giants in the eighth and gave up a leadoff triple to Nate McLouth. Bay followed with an infield single to make it first and third. Shortstop Brian Bocock robbed Nady on a diving stop up the middle, turning a double play, but McLouth scored from third giving the Pirates some insurance heading to the ninth.