Houston's Luke Scott hit a tiebreaking, three-run homer in the eighth inning that helped Roy Oswalt get his 19th career victory over the Reds, 5 to 4 .
Oswalt (5-2) allowed six hits in seven innings and the Astros rallied late in Cincinnati.
Adam Dunn and Alex Gonzalez hit back-to-back homers in the second inning for Cincinnati's runs -- only the second time in Oswalt's 22 career starts against the Reds that he gave up two homers.
Cincinnati's Kyle Lohse (1-3) matched Oswalt until the eighth, when Craig Biggio led off with a single.
After Mike Stanton walked Lance Berkman, reliever Todd Coffey sprinted from the bullpen to the mound and gave up Scott's homer to right field on a full count.