Miguel Tejada, Carlos Lee and Ty Wiggington hit homers for the Astros, while Russell Branyan, Mike Cameron and Jason Kendall added to Corey Harts two long balls for the Brewers.
Manny Parra went 5 1/3 innings to pick up his 5th win (5-2). Brandon Backe took the loss for the Astros.
Houston catcher Brad Ausmus and manager Cecil Cooper were both ejected in the 7th inning for arguing separate calls with first-base umpire Angel Campos.
The two teams wrap up the series with a day game today.