Andres Torres hit a two-run homer and Barry Zito pitched seven solid innings as the San Francisco Giants beat the visiting Houston Astros 4-3 on Sunday afternoon.

Torres’ first-inning homer got the Giants started and Zito improved to 6-1 by holding Houston to three runs and six hits in seven innings.

The victory marked the second time this season that San Francisco swept a three-game series from Houston.

The Astros had runners on first and third with two out in the ninth before Brian Wilson struck out Kaz Matsui for his ninth save of the season.

It was the second straight contest in which Wilson retired Matsui to clinch a San Francisco victory.

The game was tied at 2-2 after Houston’s Carlos Lee homered in the fourth inning. It was only Lee’s third homer of the season.

Aaron Rowand put the Giants back ahead with a leadoff homer in the sixth. Torres scored later in the inning on a wild pitch by Houston starter Brett Myers.

Houston pulled back within a run in the seventh when Kevin Cash doubled home Pedro Feliz.

Myers (2-3) went the distance, giving up four runs and five hits. He struck out seven and walked three.