Johnny Estrada hit his second grand slam of the season against Houston and Milwaukee overcame an injury to Ben Sheets to beat the Astros 9-1 on Tuesday night, moving the Brewers into first place in the NL Central.
Claudio Vargas (11-4) pitched four scoreless innings in relief of Sheets, who left with tightness in his left hamstring after giving up a run in the first. Team officials said Sheets would be evaluated on Wednesday. His status was uncertain for his next scheduled start, in Atlanta on Sunday.
The Brewers didn't need their ace against the Astros, who've lost 10 of their last 13 games.
Ryan Braun added a two-run homer and Prince Fielder stretched his hitting streak to 16 games with an RBI single for the Brewers, who moved ahead of Chicago by less than a percentage point after the Cubs' 5-2 loss to the Cincinnati Reds.
Estrada's second career grand slam capped a five-run fourth inning off rookie Felipe Paulino (0-1), who was making his first major-league start. The 23-year-old right-hander was recalled from the minors on Sept. 4.
Houston took 1-0 lead in the first inning, before Sheets departed.
Rookie Josh Anderson led off with a double down the left-field line, went to third on Craig Biggio's bunt and scored on Lance Berkman's single up the middle. Anderson is 12-for-25 since the Astros recalled him from the minors on Sept. 1.
Sheets came out to start the second inning, but signaled to the dugout that he was hurt. Manager Ned Yost walked to the mound with a trainer and the right-handed Sheets pointed to his lower left leg.
Sheets jogged around the infield and threw a warmup pitch before walking off the field.
Paulino allowed only one hit through the first three innings before crumbling in the fourth.
After Joe Dillon led off with a ground out, Braun tripled over Anderson's head in straightaway center and Fielder followed with a broken-bat single to left that tied the game at 1.
Corey Hart doubled down the left-field line and Paulino intentionally walked Gabe Gross to load the bases for Estrada, who hit a grand slam off Astros reliever Rick White at Miller Park on June 26.
This time, Estrada drove a 2-2 pitch from Paulino over the right-field wall, just inside the foul pole. Estrada is 6-for-10 with 19 RBIs with the bases loaded this season.
Left-hander Trever Miller relieved Paulino to start the fifth. He walked Dillon before Braun lined his 31st homer of the season a few feet inside the left-field foul pole.
Geoff Jenkins and Rickie Weeks hit back-to-back homers off Brian Moehler in the ninth.
Seth McClung, Derrick Turnbow and Greg Aquino combined to shut out the Astros without a hit over the final four innings.