Wainwright was helped from the field by a trainer after injuring his left ankle while stumbling out of the batter's box on his popup to first leading off the fifth inning. He allowed three hits in four shutout innings.
The 29-year-old Harris then tossed 1 1-3 scoreless innings in his major league debut after serving five years of active duty in the U.S. Navy following his graduation from the Naval Academy.
Matt Holliday hit a three-run drive in the seventh for St. Louis for his first homer of the season.
