PITTSBURGH -- It took an improbable comeback to beat the Pirates, but "improbable" seems to be the Brewers' specialty.The last month has been one big comeback, from a team looking ahead to 2013 to one pushing hard for the postseason. On Thursday at PNC Park the Brewers trailed by three in the eighth inning and were 0-for-10 with runners in scoring position, when the bats suddenly came alive, providing four runs and a sweep-clinching 9-7 win over the stunned Pirates. St. Louis is 80-70 and leads the chase for the National League's second Wild Card. The 77-72 Brewers remained 2 1/2 games behind St. Louis. The 77-73 Dodgers slipped three games back after falling to the Nationals on Thursday. Milwaukee has its first five-game winning streak this season and has won 23 of 29 games since Aug. 19. Aramis Ramirez led the way with three RBIs, including a go-ahead single in the eighth, and Norichika Aoki and Rickie Weeks also delivered clutch hits in the decisive rally. Has Ramirez ever seen a streak like this? Yes, but not by a team like this. "I played on a couple of real good teams in Chicago, and we started the season off really well. Here, we didn't do that," Ramirez said. "Hopefully, it's not too late." The Brewers swept the three-game series from the Pirates, who have piled up losses (21 in their last 28 games) as rapidly as the Brewers have stockpiled wins. The Crew needed every one of them this week to keep pace with the Cardinals, who finished their own sweep earlier Thursday against the Astros. "We're doing everything right right now," Ramirez said. "When we pitch, we usually take care of business." Thing is, they did not pitch particularly well on Thursday, at least until the late innings. Right-hander Mike Fiers lasted only three innings in another start that raised questions about whether the heaviest workload of his young career is taking its toll. He let an early 4-0 lead slip to 4-3 on Andrew McCutchen's three-run home run and was out of the game by the fourth. The Pirates went on to tie the game against Brandon Kintzler in the fourth inning and take a 7-4 lead on Kameron Loe and Jose Veras in the sixth. The Brewers, meanwhile, had been quiet since an early outburst against Pittsburgh's Wandy Rodriguez, who fell into a 3-0 hole when Ryan Braun grounded out for his NL-best 105th RBI and Ramirez followed with a two-run homer. After that, it was an evening of missed opportunities for Milwaukee until the eighth. The Brewers left the bases loaded in the first inning, stranded men in scoring position in the fifth, sixth and seventh, and, when Nyjer Morgan popped out against Pirates reliever Chad Qualls with two men on base in the eighth, they were hitless in 10 at-bats with runners in scoring position. But Qualls fell behind the next hitter, Aoki, who drilled a double off the right-field wall. Weeks greeted another reliever, Chris Resop, with a tying triple to the deepest part of left-center field, and, after Ryan Braun was intentionally walked -- the right move, Ramirez said -- Ramirez grounded a single up the middle for an 8-7 lead. "I felt the job Qualls has done against right-handed hitters since he's been here [spoke for itself]," Pirates manager Clint Hurdle said. "Besides, Qualls is the guy who has pitched more eighth innings than anyone in that bullpen." Francisco Rodriguez held the Brewers' lead in the eighth inning, Logan Schafer delivered an insurance RBI in the ninth and John Axford logged his 31st save with a vintage 2011 outing. Axford struck out the side -- McCutchen and Neil Walker on weak swings at sliders and Pedro Alvarez swinging under a high fastball. Axford has converted 13 consecutive save opportunities. "It would have been easy for us to not fight and come back, but the guys keep doing it," Brewers manager Ron Roenicke said. The comeback pushed to the background concerns about the rookie right-hander Fiers, who stranded a runner in each of the first two innings but was burned in the third when McCutchen blasted a three-run home run to straightaway center field. The deep blast cut a 4-0 Brewers lead to 4-3. Fiers escaped the inning with two more flyouts, including one by Garrett Jones that came two pitches after Jones hammered a would-be homer just foul down the right-field line. But after three innings and 81 pitches, Fiers' day was done. He was pitched deeper into this season than any in his baseball life, and the numbers are beginning to change. Fiers pitched to a sparkling 1.81 ERA and .218 opponents' batting average in his first 13 appearances, including 12 starts. In the eight starts since, he has a 6.75 ERA and a .298 opponents' average. He is up to 172 1/3 regular-season innings between Triple-A Nashville and Milwaukee, compared to 128 innings in 2011, plus 28 1/3 innings in Venezuela last winter for a total of 154 1/3. "I don't think that's the deal for me. I still feel strong," Fiers said. "I'm just not hitting my spots. I'm not getting it done. I have pitched the most innings I have ever pitched, but I'm not going to use that as an excuse. It's just bad pitching on my part." The Brewers have discussed the merits of shutting Fiers down at some point to protect his arm, but so far, they have not taken that course. Roenicke wondered aloud whether Fiers might be putting too much pressure on himself with the Brewers suddenly in the postseason picture. "This time of the year, the less they can think about what's going on and the more we can relax and just play, it's going to help us," Roenicke said. "Now, I don't know exactly with Mike. Maybe there's a little fatigue there. I don't see that when I look at his stuff. I don't think his stuff is down any, it's just location of the ball." Said Fiers: "I'm just happy we were able to rally back and win."