Carlos Zambrano carried a shutout into the sixth inning and also homered as the Chicago Cubs posted a 9-5 win at Houston on Wednesday night.

The Cubs took a 5-0 lead in the first inning against Houston starter Wandy Rodriguez (0-2). Jeff Baker opened the barrage with a two-run double and Alfonso Soriano followed with a three-run homer to left.

Zambrano (2-0) gave himself a six-run cushion with a solo shot off reliever Fernando Abad in the sixth, but he would end up needing that run after he came unglued in the bottom of the inning. Carlos Lee and Brett Wallace got the Astros (3-9) on the board with RBI singles, and after Bill Hall drove in another run with a fielder's choice, Matt Downs made it a 6-5 game with a two-run shot to left.

Zambrano was charged with five runs and seven hits in 5 2/3 frames. Rodriguez was tagged for five runs and nine hits in five innings.

Chicago (6-6) stretched the lead back to four runs in the top of the ninth. Darwin Barney doubled home Starlin Castro and then scored on an error, and Aramis Ramirez followed with an RBI single.