Recap: Pittsburgh vs. Houston

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.

Karstens threw 89 pitches, 62 for strikes.

"It was location, command, changing speeds and staying off the middle of the plate. He was very efficient," Pirates manager Clint Hurdle said.

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.

"We don't have to sneak up on anybody any more, but we have work to do," Hurdle added. "We've worked hard to get to this spot. We're making our way."

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 slide, April 16-May 8, 2005.

"Everybody's making a big deal about the road and home, the separation," Astros manager Brad Mills said. "At the same time, we want to play good solid baseball. We definitely have to make sure we get back on the right track."

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.

Jones doubled high off the wall in right field to start the second and McGehee followed with a bloop double down the right field line.

In the following inning, Karstens singled to lead off, and Neil Walker stroked a ground-rule double to left-center, a one-bouncer over the fence. After Andrew McCutchen was intentionally walked, Jones lifted a sacrifice fly to left-center, where Martinez made a running catch.

Moore advanced to second on a balk with one out in the fourth, but Karstens retired the next two batters. Houston didn't get a runner past first again until the ninth.