Making up more ground could prove difficult against Wily Peralta, who tries to become baseball's first 16-game winner Saturday night.
The Pirates (66-62) have followed a season-worst seven-game skid with back-to-back victories after winning 8-3 on Friday. Josh Harrison went 3 for 5 with a homer and a career-high five RBIs as Pittsburgh climbed within five games of Milwaukee.
Andrew McCutchen also homered in his third game back since coming off the disabled list and Jeff Locke threw six strong innings. The Pirates, who had dropped six of their previous seven at Miller Park, remain 2 1/2 games behind San Francisco for the NL's second wild-card spot.
"We all know what's at stake. We're playing for something," manager Clint Hurdle told MLB's official website.
The Pirates now look to get the best of Peralta (15-7, 3.27 ERA), who is 6-1 with a 1.59 ERA over the last six weeks. The right-hander is tied with Johnny Cueto, Clayton Kershaw and Adam Wainwright for the major league lead in wins.
"Sooner or later, you have to pay attention to him," catcher Jonathan Lucroy said when asked about Peralta's lack of national attention. "I think it's a byproduct of playing in the Milwaukee market. We're not looked at as much, which is fine. That's the way I like it, personally. But he definitely deserves a lot more credit than he's getting."
Peralta allowed five hits over six scoreless innings in Sunday's 7-2 victory at Dodger Stadium.
"I've just been pounding the strike zone and working ahead of the hitters," he said. "I've been able to locate my fastball and mix it in with some off-speed stuff."
Peralta has won four consecutive home starts behind a 1.03 ERA. He is 2-0 with a 2.25 ERA in three matchups against Pittsburgh.
The Brewers (71-57) are on the verge of losing three straight for the first time since July 27-29. Ryan Braun went 2 for 5 with a two-run homer - just his second since July 25 - but Milwaukee was 1 for 7 with runners in scoring position Friday.
"We just didn't get the big hit when we needed it," manager Ron Roenicke said.
The Brewers will try to bounce back against Edinson Volquez (10-7, 3.58), who is 2-0 with a 2.16 ERA in four starts this month. The right-hander yielded four runs - one earned - over 6 1-3 innings in Sunday's 6-5, 11-inning loss at Washington.
Volquez has pitched well against the Brewers since the start of last year, going 3-1 with a 2.56 ERA. Jean Segura is hitless in 14 at-bats in their matchups and Mark Reynolds is 1 for 12.
Reynolds is mired in a 1-for-17 slump, dropping his average to .202. Segura is 4 for 28 over a 10-game stretch and 2 for his last 21 against the Pirates.
Harrison is batting .344 with two homers and eight RBIs in his last nine games against the Brewers.
Pittsburgh has lost 10 of 14 to Milwaukee this year.