PITTSBURGH -- The Brewers entered Pittsburgh on Monday with their three premier pitchers lined up to try to extend their lead in the National League Central race.

Unfortunately, Corbin Burnes struggled to keep the Pirates off the barrel, leading to a 4-2 loss for Milwaukee in the series opener at PNC Park. The outcome trimmed the Brewers’ lead in the NL Central to 2 1/2 games after the Cubs defeated the Giants on Monday afternoon.

Burnes has historically been strong against the Pirates, posting a 7-1 record with a 3.33 ERA entering Monday. However, after striking out six times in three scoreless innings, Pittsburgh’s offense began to square up a handful of pitches over the heart of the plate.

• Games remaining: at PIT (2), at NYY (3), vs. MIA (4), vs. WAS (3), at STL (4), at MIA (3), vs. STL (3), vs. CHC (3)
• Standings update: The Brewers have a 2 1/2-game lead over the Cubs atop the National League Central. With head-to-head records determining a potential tiebreaker, the clubs are tied, 5-5, with three games remaining in the season series.

In the fourth inning with a runner on third, Burnes delivered a 1-0 cutter to Jack Suwinski that began on the outer part of the plate and tailed to the middle. Suwinski turned on it for a homer to straightaway center field.

Then, in the bottom of the fifth, Burnes got to two outs before struggling to get the third. Ke’Bryan Hayes drew a full count then ambushed a hanging center-cut curveball on a rope over the North Side Notch in left-center field. Reynolds pulled a double down the right-field line to bring up Andrew McCutchen, who Burnes pitched away, away, away. But his sixth offering to the former Brewer slid over the middle of the plate, and McCutchen sent it off the wall in left field to put the Pirates up by two.

“The second time through, we just left pitches right over the middle of the plate, and they hit them,” Burnes said. “Veteran hitters in McCutchen and Reynolds aren’t going to miss those. That’s a lineup that doesn’t chase a ton and doesn’t punch out a lot, so to get the seven punchies then four of the knocks came with two strikes that were just breaking balls right down the middle, we’ve got to be able to finish.”

Though the mistakes were crucial, it wasn’t a night to completely flush for Burnes. One of the high points of his start was issuing no walks to the Pirates. It’s the first time he’s not allowed a walk in a game since June 7 and only the third time this season.

Burnes said he’s worked to make an adjustment that got him back to what made him so dominant in his 2021 NL Cy Young Award-winning season.

“It showed early on,” Burnes said. “It showed that we were able to get to two strikes quickly, got some punchouts quickly when we needed to, but just when we got to the second time through the order, we just made mistakes over the plate.”

Burnes showed his resiliency after the tough fifth inning by coming back to pitch a 1-2-3 sixth inning, bringing his pitch total to 105 pitches -- the fourth start in his past six in which he’s given the Brewers more than 100 pitches.

This is not a surprise to the Brewers, but it is a boon. Milwaukee is in the midst of a stretch of 29 games in 31 days to end its regular season, all the while fighting for every game to keep distance against the Cubs in the standings. It will take every inning the starters can give to keep the bullpen fresh in this stretch.

“Corbin does that,” manager Craig Counsell said. “He had a rough fifth inning, but he came out and had a good sixth inning. He’s consistent like that, for sure. That’s always meaningful when you get your starter through six.”

The Brewers have no reason to panic. Despite dropping a game in the division race to the Cubs on Monday, they have two-time All-Star Brandon Woodruff lined up for Tuesday and reigning NL Pitcher of the Month Freddy Peralta slated for Wednesday.

“It’s really nice this time of the year,” said Bryse Wilson, who pitched a scoreless eighth, of the starting depth, “because we’re fairly confident that we won’t have to come in before the sixth inning, which is super nice. We have a lot of guys who have thrown a lot of innings, and those guys have all gotten better as the year’s gone on.  It’s really nice. You have a lot of confidence going into the game.”