Hunter Pence hit one of San Francisco's three solo homers and reliever Yusmeiro Petit threw three sharp innings after starter Matt Cain left with a strained right hamstring as the Giants beat the Colorado Rockies 5-1 on Wednesday night.
Pablo Sandoval and Brandon Crawford also connected for the NL West-leading Giants, who won at Coors Field for just the fifth time in 15 games dating back to last season.
Cain didn't allow a hit through three innings, before giving way to Petit (3-1). He and four other relievers limited the best offensive team in the majors to just five hits.
Jhoulys Chacin (0-3) worked 5 2-3 innings and allowed three runs, including a homer to Pence in the fourth and another to Sandoval two innings later.