Pittsburgh, PA (Sports Network) - Zach Duke pitched well into the eighth inning, as the Pittsburgh Pirates downed the Houston Astros, 5-2, in the second of three-game set.

Duke (3-4) scattered seven hits and two runs over 7 2/3 innings, fanning two and walking two for the Pirates, who have split their last six games. Raul Chavez had a two-run single and a sacrifice fly for Pittsburgh.

Roy Oswalt (4-6) was touched for nine hits and four runs over six innings, with four strikeouts and a walk. Ty Wigginton homered for Houston, which has dropped six of seven.

Wigginton gave the Astros the early edge with his leadoff homer to left in the third, but the Bucs moved in front with a three-spot in the fourth. Jason Bay singled to left with one out, and Oswalt beaned Xavier Nady. Adam LaRoche reached on an infield single, and Bay came home with Pittsburgh's first run.

After a Jose Bautista ground out Chavez laced a single to left, plating both runners for a 3-1 Pirates lead.

Pittsburgh tacked on another run in the fifth. Jack Wilson led off with a single to center, and was picked off first, but moved to second when Lance Berkman was called for interference on the run down. Nate McLouth then lined a single to left, allowing Wilson to come around for a 4-1 lead.

The Astros got one run back in the sixth. Miguel Tejada worked a one-out walk and stole second, and Carlos Lee lined a two-out single to left, scoring Tejada to pull Houston within two runs.

LaRoche worked a leadoff walk in the ninth, moved to second on a Jose Bautista sacrifice bunt, and headed to third on an Oscar Villarreal wild pitch. Chavez then lifted a fly ball to center, deep enough to score LaRoche with an insurance run.

Matt Capps threw a 1-2-3 ninth for his 12th save of the season.