Daniel Descalso homered and drove in three runs and the Colorado Rockies snapped the San Francisco Giants' eight-game winning streak, taking the second game of a rain-soaked doubleheader 5-3 on Saturday night. Descalso had a run-scoring groundout in the fourth and added a two-run homer in the sixth off spot starter Yusmeiro Petit (1-1). Descalso's homer off a 79 mph changeup put Colorado ahead 4-2, marking the first time the Giants trailed by more than a run since May 9.