Brewers win 6th straight, complete sweep of Astros
Jonathan Lucroy and Yuniesky Betancourt drove in two runs apiece before Fielder's key single.
Milwaukee (60-49) tied its season-best six-game winning streak and moved 11 games over .500 for the first time in more than two years to maintain its division lead over St. Louis.
The Astros traded two-thirds of their starting outfield in the last 48 hours, sending away their strongest defensive player by dealing Bourn to the Braves for outfielder Jordan Schafer and three minor-league pitchers.
Brewers reliever Francisco Rodriguez (4-2) failed to protect the lead in the eighth after he threw a wild pitch with runners on second and third with two outs that allowed Jason Bourgeois to score and tie the game at 4, costing starter Chris Narveson the chance at the victory.
But the Brewers bounced right back off Fernando Rodriguez (2-1) when Braun doubled off the wall and Fielder punched a single just past the infield into center. Braun easily beat Bourgeois' throw to the plate.
John Axford converted his franchise-record 28th consecutive save and 31st of 33 chances this season with a perfect ninth.
Narveson left with two on and two outs in the seventh for Takashi Saito, who walked pinch hitter Angel Sanchez to load the bases but forced Jose Altuve to pop up to end the threat. No Brewers starter has given up more than three runs in 16 straight starts, with the rotation posting a 2.10 ERA in the span.
Milwaukee took a 2-0 lead in the second inning when Jose Lopez singled and scored on Betancourt's double. Betancourt took third on an errant throw from Clint Barmes at short and scored on Lucroy's suicide squeeze.
Bourgeois, playing in Bourn's spot, hit his first home run in almost two years with a three-run shot in the fourth, but Milwaukee tied it in the bottom of the inning on Lucroy's double.
Milwaukee went ahead 4-3 in the sixth on Betancourt's fielder's choice after Fielder broke up a double-play attempt by sliding hard into second base.
The Brewers decided to stay away from major moves at the non-waiver trading deadline after kicking off the July action by dealing for Rodriguez just after the All-Star game. Milwaukee is a majors-best 39-14 at home and will face the Cardinals in a three-game series beginning Monday night to finish a nine-game homestand.
Houston, meanwhile, remained busy retooling its team for the second straight year.
There was no goodbye for Bourn in the middle of the game as when Hunter Pence was removed Friday night to head to Philadelphia. Bourn, a two-time Gold Glove winner, never came to Miller Park after he was traded four hours before the Astros finished this season-long 10-game trip with a thud at 2-8.
Houston (35-73) is well on its way to its first 100-loss season in franchise history. After dealing away Roy Oswalt and Lance Berkman last year, they've sent Bourn, Pence and second baseman Jeff Keppinger packing in the last 13 days to acquire Schafer, eight minor leaguers and a player to be named.
NOTES: Brewers 3B Craig Counsell set the franchise mark for at-bats without a hit at 43 with a groundout in the fourth. He finished without a hit and his skid is now 44 at-bats. ... The Astros will call up OF Luis Durango on Monday to fill Bourn's spot on the roster. ... Schafer is on the 15-day DL with a fractured finger, but the Astros believe he'll be ready to be inserted in the starting lineup by mid-August. Schafer is hitting .240 with a homer, seven RBIs and 15 steals in 52 games for the Braves.