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It may be thin, but the first-place Milwaukee Brewers kept place club tonight in the opener of a three-game series against the Houston Astros, who try to win five straight for the first time this season.

The Brewers held a double-digit lead over the Cardinals for the top spot in the division, but was swept in a three-game set by the club to begin the week. Thursday's 8-4 defeat marked the first time Milwaukee was swept at home this season.

Jonathan Lucroy, Corey Hart and Prince Fielder all homered for the Brewers, who still lead the Cardinals by 7 1/2 games for first place. Hart ran his hitting streak to 15 straight games and Fielder became the first player in club history to notch five straight seasons of at least 30 home runs, but starter Yovani Gallardo yielded a career-high four homers over his 4 2/3- inning outing.

The Brewers now hit the road and turn to right-hander Zack Greinke, who is a perfect 10-0 at Miller Park this season but just 3-5 with a 5.56 earned run average in 10 outings on the road.

Greinke had a five-start winning streak end with a dreadful outing in Pittsburgh on Aug. 22, giving up seven runs over 6 1/3 innings, but rebounded with a home victory over the Cubs on Sunday. He allowed a run over 7 2/3 innings of that one, giving him a 4.05 ERA in 22 starts this year.

The 27-year-old has won both of his career starts against the Astros, including a win on Aug. 7 in which he gave up a run and struck out six over seven frames. He has allowed two runs in 15 career innings versus Houston.

The Astros come in riding a season high-tying four-game winning streak and finished off a three-game sweep of the Pirates with Wednesday's 2-0 victory. J.A. Happ hurled seven scoreless innings to get the win, scattering three hits and a walk while striking out six in Houston's first home sweep of the season.

"There's definitely a lot more energy and that's always a good thing," Happ said.

Carlos Lee had a pair of hits to run his hitting streak to a season-high 12 straight games.

With Brett Myers away from the team pending the birth of his fourth child, Lucas Harrell will come up from Triple-A Oklahoma City to make the spot start.

Harrell made three appearances with the White Sox earlier this year, posting a 7.20 ERA before getting claimed off waivers by Houston in July. The 26-year- old righty will make his Astros debut tonight with his fourth career start.

Harrell, who has never faced the Brewers, went 5-2 with a 1.72 ERA at Triple A and is expected to stick with the big league club for the rest of the season.

"Lucas has done a good job for us down there, and his last several starts have been outstanding," Astros general manager Ed Wade said on his team's website. "And the reports have been very solid. He was going to come up in September anyway, but he'll come up and get a start here. Hopefully he takes advantage of it and gives our staff a chance to see what it's all about."

The Brewers have won six straight versus the Astros and nine of the 12 overall meetings this year.