Pittsburgh, PA (Sports Network) - Jeff Karstens pitched eight shutout innings and the Pittsburgh Pirates completed a four-game sweep of the Houston Astros with a 2-0 victory Thursday night.

Karstens (2-2) allowed four hits, walked one and had a season-high eight strikeouts. The right-hander, who was making just his sixth start of 2012 due to being on the disabled list, retired the last eight hitters he faced.

Joel Hanrahan walked Jed Lowrie to start the ninth, but Scott Moore grounded into a double play. After J.D. Martinez walked and went to third on a wild pitch, Hanrahan retired Chris Johnson on a fly ball to right to nail down his 22nd save of the season.

Casey McGehee doubled in a run in the second inning. Karstens singled to start the third and scored on a Garrett Jones sacrifice fly, as the NL Central leaders posted their eighth victory in nine contests. The Bucs, who are 10 games over .500 (46-36), posted their first four-game sweep of the Astros in Pittsburgh since July 19-21, 1979 at Three Rivers Stadium.

They also sent the Astros to their eighth loss in a row overall and 10th straight on the road. It's Houston's first 10-game skid on the road since an 11-game skid, April 16-May 8, 2005.

Bud Norris (5-6) gave up five hits and the two runs over seven innings. He also had six strikeouts, but dropped his fifth consecutive start.

The Sports Network