The Pirates, who dropped six of their final eight games, end the year at 78-83-1.
The Cardinals broke open Sunday's game with a six-run seventh in which they tallied six straight hits off Pittsburgh's relievers. It came a half-inning after the Pirates had evened the game at 4 with a John Jaso home run off Jonathan Broxton. That blast came a half-inning after Matt Carpenter provided a 4-2 lead with a dramatic three-run shot.
That blast kept Adam Wainwright from picking up his 14th victory, though he did pitch the Cardinals to wins in six of his final seven starts.