J.A. Happ dominated in his third career shutout to outduel Jake Westbrook as the Houston Astros took down the St. Louis Cardinals, 3-0, on Monday.

Carlos Lee and Brett Wallace each had RBI doubles for the Astros, who finished with nine hits and have won seven of nine.

Happ (5-2) allowed just two hits while walking one and striking out four in his first complete game since joining the Astros prior to the trade deadline. The 27-year-old left-hander has allowed three runs or less in six of seven starts with his new team.

Westbrook (7-8), who was the Cardinals’ big acquisition at the deadline, once again came out on the wrong end despite turning in a quality start. The veteran right-hander was charged with three runs and nine hits while walking one, striking out three and inducing 15 groundouts in seven innings.

Lee provided Happ with all the support he would need in the first when his double plated Hunter Pence. Houston added two more runs in the seventh when Wallace doubled in a run and then scored from third on a double-play groundout.