The two clubs entered the set with identical 74-72 records, sitting 2 1/2 games back in the National League Wild Card race.
The Brewers, who took the first game from the Pirates on Tuesday night, have now won 21 of their past 27 to reinsert themselves into the postseason chase.
Brewers manager Ron Roenicke said that he couldn't pinpoint one thing behind the turnaround, saying it's a culmination of facets coming together at the right time.
"At the beginning of the season, there were a lot of points where we had streaks where we didn't swing the bats well at all, [but] the second half of the season, we have really swung the bat well, and we're scoring a lot of runs," Roenicke said. "The bullpen was good early, then we had that stretch where we weren't so good. We were bad. Then we have this stretch now where we're pitching really well again. The starters have probably been the most consistent thing we've had."
Roenicke wants to "keep it the same" as his team heads into the final stretch of the season, hoping to land that second Wild Card berth.
Marco Estrada, who takes the mound for Milwaukee on Wednesday, has been a major factor in the club's success of late.
Estrada has won three of his past four decisions, including a stellar start against the Pirates on Sept. 1, when he allowed just one run through seven innings while striking out 10.
The Pirates will counter with a new weapon of their own, as Kyle McPherson toes the rubber for his first Major League start.
McPherson is filling in for James McDonald, who was removed from the rotation this past weekend in Chicago.
McPherson was the organization's Minor League Pitcher of the Year in 2011 and is the club's No. 10 prospect according to MLB.com. The 24-year-old went 12-6 with a 2.96 ERA between Class A and Double-A stints after missing the first half of the season with inflammation in his shoulder.
"He's a power pitcher," said Pirates manager Clint Hurdle. "Reports on his development have been very good, and I'm eager to see what he can do in a game with a lot at stake."
Brewers: Hurting Hart not ready to play
The Brewers continue to play without first baseman Corey Hart, who remains out with torn tissue along the arch of his left foot.
Hart reported no progress on the injury again on Tuesday and continues taping the foot and wearing custom shoe inserts to ease the pain.
"If baseball was all in straight lines, I'd be good to go," Hart said. "I feel like it's improving, but not to where I need it. It's tough, because I want to go out there and play every day, but there are so many things, that I think I would hurt our team if I was in there. I feel like I couldn't score from first [on a double] or score from second [on a hit]. Quick plays at first are going to be hard, [moving] back and forth."
Rickie Weeks earned the Brewers' nomination for the Roberto Clemente Award, marking the second time in his career the 30-year-old has been chosen.
Weeks, who is involved in a variety of charities around the area, was also nominated in 2010.
"A lot of time, people forget about doing off-the-field stuff, community relations and trying to give back," Weeks said. "I take pride in doing that. It just feels good when they recognize you for that."
Pirates: McCutchen thriving with support
There's no doubt that Andrew McCutchen has been a big part of the Pirates' turnaround this season, but it's certainly been far from a one-man effort.
Hurdle said that having such players as Pedro Alvarez, Garrett Jones and Neil Walker surrounding McCutchen helps take off some of the pressure and urgency that comes with being the biggest bat in the lineup.
"I think as you get through a season like we have this year, where other people have come up and performed, you don't relax by any means, but you can understand, 'I don't have to do this by myself,'" Hurdle said. "It's probably something every really good player fights from time to time, but I do think with experience and maturity that it probably does lessen."
Opposing pitchers have given McCutchen a little bit less to worry about. His 14 intentional walks are the most for the Pirates since Brian Giles received free passes 24 times in 2002.
Reliever Chris Resop was named the Pirates' candidate for the 2012 Roberto Clemente Award. Resop works in both his home state, Florida, and in the Pittsburgh area to help raise money and awareness on behalf of cancer patients and children.
"Obviously, I don't do it for recognition, it's just something I enjoy, giving back to the community and helping kids out whenever I can," Resop said. "I've been fortunate to live the life I've lived, and I have time to do it before I come to the field. I really cherish and enjoy it."
The Pirates rank fourth in the NL in homers, with 157, but 97 of those have come on the road. They have hit only one in their past seven home games.
Brewers pitchers lead the Majors in strikeouts, with 1,269 -- the most in franchise history for a single season.