Astros 5, Pirates 1:
Edgar Gonzalez threw 5 1/3 solid innings in his Houston debut and Brett Wallace had a three-run homer among his three hits as visiting Houston won for only the fourth time in 20 games.
Gonzalez (1-0) had not made a major-league start since 2009 with Oakland before the Astros signed him out of the Mexican League in late August. The right-hander allowed one run on five hits and struck out five for his first major-league win since 2008 with Arizona.
Houston relievers Mickey Storey and Wesley Wright combined to work the final 3 2/3 innings without allowing a baserunner.
The Pirates have lost 17 of 24 to fall out of contention in the National League Central. They also slipped 2 1/2 games behind St. Louis for the final NL wild card spot.
Pirates left-hander Jeff Locke got off to a shaky beginning in his first major-league start of the season. He allowed three straight singles to start the game, and the Astros struck first on Matt Downs' RBI groundout later in the inning.Justin Maxwell added an run-scoring groundout in the third and Wallace launched his seventh homer into the right-center field seats to make it 5-0.
Pittsburgh's lone run came in the fifth, when Pedro Alvarez tripled and scored on Clint Barmes' single.
GAME NOTEBOOK: The Astros had 10 hits, only the second time in their past 10 games they've reached double digits. … Houston won for only the third time in 12 games against the Pirates this season. … The Astros sent RHP Mark Hamburger to Triple-A Oklahoma City to clear a spot for Gonzalez.