Cards' Manager Tony La Russa batted Pujols clean-up for the first time in nearly seven years and the reigning National League MVP responded by breaking out of a slump, stroking three singles and scoring two runs.
The win gave the Cardinals their 12th victory in 14 games against Washington but only their fourth win in 13 games overall.
Colby Rasmus contributed two hits, scored two runs and drove in one run. Freese's hit highlighted a four-run St. Louis first inning.
Kyle Lohse (1-3) got his first win of the year after allowing only one earned run on six hits and a walk through six-plus innings.
Craig Stammen (1-2) absorbed the loss for the Nationals, surrendering four runs on six hits and two walks while fanning four in six innings.