PITTSBURGH -- An inability to beat the lowly Milwaukee Brewers cost the Pittsburgh Pirates a chance to gain ground in the National League Central race Tuesday night.

Logan Schafer and Luis Sardinas, who entered the game earlier as reserves, hit consecutive run-scoring singles with two outs in the top of the 13th inning, giving the Brewers a 6-4 victory, their seventh straight over the Pirates since the All-Star break.

"Both sides were scrapping and battling," Schafer said. "Just one of those games that you fire back at each other and someone comes out on top."

The Pirates (83-56) remain 4 1/2 games behind St. Louis in the NL Central, as the Cardinals lost at Cincinnati. Pittsburgh's lead for the first NL wild card was sliced to 2 1/2 games over the Chicago Cubs, who were rained out at Philadelphia.

With the score tied at 4-4, pinch hitter Nevin Ashley struck out to begin the 13th but reached first on a wild pitch by reliever Radhames Liz (1-4). Shortstop Jean Segura hit a one-out single, and after catcher Martin Maldonado struck out, Schafer and Sardinas delivered.

Schafer came into the game as the center fielder in the ninth inning as part of a double switch. Sardinas came on in the 10th inning as a defensive substitute at second base for the Brewers (62-78), who trail St. Louis by 26 games in the division standings.

Liz allowed three runs, four hits and four walks in two innings. He became the first Pirates reliever to lose since June 25, a span of 19 decisions.

"He pitched twice in Milwaukee (last week), they've seen him there a little bit," Pirates manager Clint Hurdle said. "He's pitched multiple innings already. He's pitched effectively. The command was a little erratic tonight."

The Pirates fell to 24-35 inside the NL Central.

Brewers right fielder Ryan Braun had two hits and two RBIs, and first baseman Adam Lind added two hits. Left fielder Khris Davis hit a two-run homer in the first inning, and Braun had an RBI single as Milwaukee took a 3-0 lead.

Left fielder Gregory Polanco and center fielder Andrew McCutchen both hit game-tying home runs for the Pirates. Catcher Francisco Cervelli had three hits and reached base five times, and second baseman Josh Harrison and third baseman Jung Ho Kang added two hits each.

Both teams scored in the 12th inning, with Polanco's eight homer in the bottom half tying the game 4-4 and pinning closer Francisco Rodriguez (1-3) with just his second blown save of the season in 36 opportunities.

The Brewers went ahead 4-3 in the top of the inning on an RBI single by Braun, who is 18-for-42 (.429) in his past 10 games.

Right-hander Kyle Lohse pitched a scoreless ninth for the second save of his 15-year career, both coming this season.

McCutchen tied the game at 3-3 in the eighth with his 22nd home run, a solo shot into the right field stands off rookie reliever Corey Knebel.

The Pirates drew within a run in the seventh when pinch hitter Travis Snider drew a bases-loaded walk with two outs off reliever Jeremy Jeffress.

Pirates right-hander A.J. Burnett came off the disabled list to make his first start since July 30. He allowed three runs and three hits -- all in the first inning -- during a five-inning stint. Burnett struck out three and walked two.

The 38-year-old, who was sidelined by a torn flexor tendon in his elbow, said nerves did not affect his poor first inning. He is winless in his past seven starts against the Brewers.

"I'm too old to be amped up over the start," Burnett said. "There's no (excuse regarding the) first inning, haven't pitched in a long time, none of that crap. Pitched it down the middle, and they did what a big league hitter is supposed to do to them."

Brewers right-hander Wily Peralta gave up two runs and five hits in six-plus innings with three walks and two strikeouts.

"It was a long wait, but it was worth it," Brewers manager Craig Counsell said. "Somehow, some way we got it done tonight. We just kept playing and finally prevailed."

NOTES: Pirates LF Starling Marte was removed in the top of the 10th inning because of discomfort in his left shoulder, and he is listed as day-to-day. He was hit by a pitch in the eighth inning. ... Brewers C Jonathan Lucroy missed his second straight game with a concussion, and manager Craig Counsell said there is no timetable for his return. ... The Brewers claimed OF Daniel Fields off waivers from Detroit and assigned him to Double-A Biloxi, where he will take part in the Southern League playoffs. ... Brewers RHP Jimmy Nelson (11-11, 3.86 ERA) will face Pirates RHP Charlie Morton (8-7, 4.07) on Friday night in the second game of the four-game series.