De La Rosa (13-6) yielded three runs (two earned) on three hits and three walks. He struck out three in logging a third victory in three starts.
Matt Belisle and Rex Brothers teamed up for 1 2/3 scoreless relief innings and Rafael Betancourt hurled a 1-2-3 ninth for his 16th save as Colorado rebounded from a 5-4 loss in Monday's four-game series opener.
Troy Tulowitzki bashed a two-run homer in the first inning, putting the Rockies ahead to stay, and Wilin Rosario also went deep for the winners.
Phillies starter Tyler Cloyd (2-3) was touched for five runs on eight hits over six innings.
Chase Utley and Domonic Brown each drove in a run for Philadelphia.
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