Pinch-hitter Lane Thomas led off the bottom of the seventh with a home run down the left-field line, stretching the Cardinals lead to 11-4.
Colorado picked up an unearned run in the top of the seventh, getting a two-out double from Nolan Arenado and then scoring when Harrison Bader misplayed Ryan McMahon's drive to the gap in right-center field.
In the Cardinals' sixth, Paul Goldschmidt led off with a double and scored on a two-out single by Yadier Molina. After six, the home team lead 10-3.
The Cardinals erupted for six runs in the second, rallying to take control of Sunday's game at Busch 6-2.