Dale Murphy's two-run homer tied the score in the seventh and Alex Trevino broke the deadlock with a leadoff home run in the eighth inning for Atlanta at home.
Trevino, who came in as a pinch runner for catcher Bruce Benedict in the sixth, hit a 2-1 pitch off Frank DiPino (4-8) over the left field fence for his fifth home run in a six-year major league career. Donnie Moore (4-3) went two innings for the victory.
Atlanta tied the score, 7-7, in the seventh on Murphy's league-leading 30th home run. Nine of Murphy's homers have come against Houston.
"Trevino may not have hit many home runs in his career, but he can sure hit the fast ball," said Denis Menke, an Astros coach. "And Murphy always wears us out."
Murphy has hit safely in 10 of his last 11 games and is batting .419 in his last 19 games.
Atlanta first baseman Milt Thompson, a 1977 graduate of Magruder High School in Rockville, Md., singled and doubled in three at bats in his major league debut. Thompson had just been called up from the Braves' Class AAA affiliate in Richmond.