It was the ninth consecutive loss for the Astros, who managed only a first-inning run against Yovani Gallardo and two relievers.
Norichika Aoki and Braun hit home runs in the opening inning and Rickie Weeks added a two-run shot in the sixth.
Gallardo (7-6) went six innings while giving up a run on four hits to collect the victory. The only run he allowed came on a homer by Scott Moore.
J.A. Happ (6-9) surrendered seven runs on nine hits in 6 1/3 to take the loss.
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