Brewers win 5th straight
Corey Hart began a four-hit night with a leadoff homer in the first for NL Central-leading Milwaukee, which earned its fifth consecutive win and stayed 1 1-2 games ahead of St. Louis. Fielder and Jonathan Lucroy had three hits apiece.
Fielder's drive in the seventh was the second-longest in Miller Park's 10-year history and a punctuation mark for a Brewers offense that had struggled over the last 10 days.
Gallardo (12-7) allowed an unearned run and four hits, retiring 15 of 16 at one point. He also struck out seven and walked none while improving to 6-0 with a 3.50 ERA in his last six starts against Houston dating to 2009.
Strong starting pitching has been the key to Milwaukee's recent run. Since Gallardo had an ugly outing in Colorado the first game after the All-Star break, the Brewers' starting rotation has allowed three runs or less in 15 straight starts.
Houston is well on its way to one of the worst seasons in franchise history even before trading Hunter Pence to the Phillies for three minor leaguers and a player to be named during Friday night's game.
The Astros scraped together four singles off Gallardo, including one by Michael Bourn, who also is the subject of trade rumors in the final hours before Sunday's non-waiver deadline.
Hart hit his 14th homer, Nyjer Morgan added an RBI single in the third, and the Brewers pushed across three more in the fifth against J.A. Happ.
Ryan Braun started the inning with a grounder to shortstop Angel Sanchez, who bobbled it for an error. Fielder singled and Casey McGehee followed with a sacrifice fly. After a single by Yuniesky Betancourt, Lucroy hit a two-run double to make it 5-0.
Happ (4-13), who was acquired last year from Philadelphia in the Roy Oswalt deal, gave up five runs, two earned, and 10 hits in five innings. The left-hander went 1-4 with a 7.48 ERA in five starts in July.
Fielder's 24th homer came off Aneury Rodriguez and landed beyond the right-field bleachers, hitting a stadium support below the Brewers' clock to give Milwaukee a 6-1 lead and its biggest offensive output since scoring 11 runs in a win at Arizona on July 19.
The Astros scored an unearned run off Gallardo on Sanchez's RBI single in the sixth. Pinch-hitter J.D. Martinez doubled in another run in the eighth in his first major league at-bat after taking the roster spot of Pence.
NOTES: Russell Branyan owns the Miller Park record with a 480-foot blast in 2004. ... The Brewers traded a minor leaguer to Washington for utilityman Jerry Hairston Jr., who arrived at the ballpark shortly after the game began and was seen in the dugout in the second inning. ... The Astros assigned 1B-OF Jonathan Singleton to Class-A Lancaster and RHPs Jarred Cosart and Josh Zeid to Double-A Corpus Christi. The three were part of the Phillies' package for Pence. ... It was the 16th sellout at Miller Park this season with 44,306 in attendance.