HOUSTON — Carlos Villanueva may have retired the first 11 batters he faced, but he couldn't get anyone out in the sixth inning.

The Brewers' right-hander gave up four runs on back-to-back-to-back home runs in the sixth inning of Milwaukee's 7-4 loss to the Houston Astros on Friday night.

The Astros hit five homers in the game.

Despite his flawless start to the game, Villanueva (1-3) wound up allowing nine hits and six runs with four strikeouts in five innings.

"It's kind of striking, those first four innings giving up one hit and then giving up eight hits," Brewers manager Ned Yost said. "It just kind of snowballed. He got it up and he just didn't make the necessary adjustments."

The six runs Villanueva allowed were the most he's given up since yielding six in five innings on June 30, 2006.

"I felt pretty good the first couple of innings," he said. "I kept the ball down and was executing my game plan. After that I had poor pitch selection, especially in the fifth inning. I got the ball up and every time I did they hit it."

The Astros trailed 4-2 before Miguel Tejada's two-run shot to left off Villanueva with one out in the sixth.

Lance Berkman followed with his home run to almost the exact same spot in the left field Crawford Boxes to make it 5-4 and give Houston its first lead of the game.

Villanueva got a short visit on the mound from coaches after Berkman's homer but remained in the game. Carlos Lee then completed the string of home runs and chased Villanueva with his own, also to left field.

It was the fifth time in franchise history Houston had hit three straight homers.

The last time came on Aug. 31, 2004, when Berkman teamed with Carlos Beltran and Jeff Bagwell.

Hunter Pence added a pair of home runs for Houston, one in the fifth inning and another in the eighth, and Roy Oswalt (3-3) evened his record after a shaky start to the season by allowing six hits and three earned runs in six innings.

"My curveball still ain't there all the time," Oswalt said. "I threw some good sliders. Overall, I pitched good enough to win and they helped by scoring some runs."