Colorado extended its winning streak to seven games and handed the division-leading Brewers their third straight loss.
De La Rosa (2-6) gave up both Milwaukee runs on four hits and the Colorado bullpen gave up one hit over the final three innings. Huston Street struck out the side in the ninth for his 11th save.
Troy Tulowitzki cut Colorado's deficit to 2-1 with a two-out homer in the fourth off Dave Bush (3-3).
The Rockies produced two runs in the fifth on doubles by Clint Barmes, Todd Helton and Brad Hawpe, then got an insurance run in the seventh on Hawpe's ninth homer of the season.
All the wins in Colorado's current streak have come on the road.
Copyright 2009 by United Press International.