Six of Houston's eight hits came during the first-inning rally, which came against struggling A's starter Jason Hammel.
Hammel (0-4) has lost all four of his starts since he was acquired by Oakland in a deal that featured All-Star Jeff Samardzija. He was lit up in this one, departing with one out in the fifth inning after allowing all eight runs and two homers.
In contrast, Houston starter Dallas Keuchel (10-7) was superb en route to his first career win against Oakland in five tries. The left-hander yielded just a run on four hits over nine dominant innings.
Jon Singleton also homered for the Astros, while Jose Altuve extended his hit streak to 12 games with a single in the sixth.