Randal Grichuk clubbed a two-run homer in the bottom of the fifth to put the Cardinals ahead of the Rockies 2-0.
After Jason Heyward singled, Grichuk took Yohan Flande's 1-0 pitch 421 feet over the center field fence. It was his 12th home run of 2015.
Mark Reynolds singled, but Tony Cruz grounded into a double play during the next at-bat. Jaime Garcia struck out looking to end the inning.
Garcia came back out to pitch the sixth, but he gave up a leadoff single. Steve Cishek is now in to pitch for the Cardinals with no outs.