Freese's blast highlighted a big fifth inning in which the Cardinals scored five times to break the contest open, while Furcal went deep in the seventh for a 10-4 advantage.
Adam Wainwright (1-3) recorded his first victory of 2012 despite allowing four runs on five hits over seven innings. He issued one walk and struck out six.
Pirates starter Charlie Morton (1-2) was roughed up for six runs (five earned) on eight hits before being yanked after 4 1/3 frames.
Jose Tabata and Pedro Alvarez each cracked a two-run homer for the Bucs, who dropped the opener of a three-game set at Busch Stadium.