Carlos Lee posted a pair of hits, knocked in one and scored his 1,000th career run for the Astros, who have won seven of 10.
Brett Myers (12-7) worked seven innings for the win, scattering six hits and one run with 10 strikeouts.
Corey Hart homered and Carlos Gomez added an RBI hit for the Brewers, who have dropped three of four.
Brandon Kintzler (0-1) was charged in the loss for three hits and three runs and three walks while recording two outs in relief. Starter Chris Narveson lasted six frames and yielded a run on six hits while fanning seven.