St. Louis won its third in a row and Houston, owner of the worst record in the National League, has dropped four straight.
The Cardinals sent 10 men to the plate in the fourth inning against Bud Norris (2-3) and wound up leaving the bases loaded. Jay's two-run single opened the scoring, Albert Pujols added an RBI base hit and a bases-loaded walk to Allen Craig accounted for the final run of the inning.
Lohse (5-2) gave up a run on six hits and struck out three. Eduardo Sanchez needed just nine pitches to get through the ninth in a non-save situation.
Yadier Molina had three of the Cardinals' 10 hits.