PITTSBURGH — Zach Duke limited the struggling Astros to four hits in his third career shutout and Adam LaRoche homered during a five-run third inning, helping the Pittsburgh Pirates extend Houston's losing streak to five games with a 7-0 victory Monday.

Freddy Sanchez had three doubles, two of them starting run-scoring innings, and the normally slow-starting LaRoche had three hits as the Pirates won their home opener for the first time since 2004.

Duke (2-0), coming off a 5-14 season, followed up a 7-4 win at St. Louis on Wednesday in which he gave up one earned run in 6 1-3 innings by pitching even better, striking out five and walking two while throwing 120 pitches.