HOUSTON -- Craig Biggio never tries to hit home runs, so his National League record for leadoff homers is a little strange to him.
Biggio gave Houston a quick lead with his 43rd leadoff homer and Brandon Backe had his best outing since returning from the disabled list, leading the Astros to a 7-0 victory over the Milwaukee Brewers on Saturday night.
Biggio, leading off for only the 10th time this season, connected off Wes Obermueller (1-4). Biggio also hit a leadoff homer May 12 against San Francisco and has 22 home runs overall this season.
"Home runs just come from accidents by me," Biggio said. "I just try to hit it solid and sometimes they go out. The record is nice to have but I'm not trying to hit them.
"But it was good to help us get off to a fast start. It's always nice when you get any pitcher a run in the first. And Brandon pitched real well tonight."
Backe (9-8) made his third start since returning Sept. 7 and got his first victory since July 18 at Pittsburgh. He pitched 6 2/3 innings, allowing six hits, walking one and striking out five.
"Brandon did a good job," manager Phil Garner said. "I'm sure it's a big confidence booster for him since he pitched well but wasn't able to get a win the first two times back."
Backe hadn't lasted more than five innings in his first two starts after coming back from a ribcage injury that kept him sidelined six weeks.
"I felt the same tonight as I did the first two times back," Backe said. "I just didn't get any breaks those other times. This time I didn't get behind in the count and I kept the ball in the park."
The Astros won their fourth straight to stay a half-game ahead of Philadelphia in the NL wild-card race. The Phillies routed Florida 10-2.
Obermueller lasted only four innings. He allowed five runs, eight hits and two walks. Obermueller fell to 1-3 on the road this season and hasn't won an away game since May 17 at Washington.
"He never got settled in," manager Ned Yost said. "He never found a groove, never got anything going. He was fighting all night long."
Obermueller agreed with Yost's assessment.
"I was a little bit jumpy at first," he said. "I fought through all four innings. I was forcing the ball to the plate.
"I think I was too amped up because we were going against a good team and I wanted to do well. I went out and tried to force the issue, rather than waiting for my pitches to work."
Jose Vizcaino added an RBI single in the first, and Orlando Palmeiro singled in another run in the second to make it 3-0. Vizcaino's second RBI single and Brad Ausmus' sacrifice fly made it 5-0 in the third inning.
With Biggio on third and Lance Berkman on first in the sixth, reliever Justin Lehr appeared to pick off Berkman. But third base umpire Mike Reilly called a balk on Lehr, scoring Biggio and sending Berkman to second.
Jason Lane followed with a run-scoring double to give Houston a 7-0 lead.
- Houston's Morgan Ensberg made his first appearance since injuring his wrist Sept. 5, when he was hit by a pitch from Philadelphia's Brett Myers. Ensberg pinch hit in the seventh inning and beat out an infield single.
- The crowd cheered loudly when manager Phil Garner and wife Carol rode onto the field on motorcycles in the pregame. The ceremony was to highlight the Garners' charity motorcycle ride earlier in the day that raised $20,000 for Mothers Against Cancer.