The blast gave St. Louis a 4-1 lead in the bottom of the fourth inning, one which it never relinquished.
Chris Duncan hit a two-run homer and also knocked in three for the Cardinals. One run scored on Shane Victorino's eighth inning fielding error, another scored on Jose Mesa's wild pitch in the same inning.
Winner Adam Wainwright (6-6) yielded two earned runs and seven hits in six innings.
Loser Adam Eaton (7-5) have up six earned runs and eight hits in 5 1/3 innings.
LGBT community has 'bullied the American people': Bachmann
Ohio bar shooting arrested, charged with murder