Astros 8, Cardinals 2: Chris Johnson hit his first career grand slam and Bud Norris tossed six strong innings as the Astros extended their winning streak to five games.

Norris (2-1) gave up one unearned run on three hits and improved to 7-2 with a 2.17 ERA in 11 career starts against the Cardinals.

After Carlos Beltran’s RBI single gave St. Louis an early lead, the Astros answered in the bottom of the first with Johnson's grand slam off Jaime Garcia (2-2), who allowed six runs on four hits and four walks over six innings.

Houston added to its lead in the fourth with Justin Maxwell’s run-scoring double and Norris’ sacrifice fly.

St. Louis, which has lost three straight, was limited to six singles and left seven runners on base.

Jed Lowrie hit his fourth home run in the bottom of the eighth for the Astros, who have won the first five games of their nine-game homestand.

GAME NOTEBOOK: St. Louis' Lance Berkman (calf) is eligible to come off the disabled list, but he likely won’t be activated until at least Monday. … The Astros’ J.D. Martinez is hitless in his last 14 at-bats after going 0-for-4 on Saturday. … Houston has won six straight games at Minute Maid Park for its longest winning streak at home since July 27-Aug. 9, 2010. … The Astros’ top three hitters went a combined 0-for-11. … The Cardinals have scored in the first inning in each of their last five games.