MILWAUKEE -- If the Cubs are going to contend, they can't afford to make mistakes like the ones Darwin Barney made in the fifth inning Friday.
Starlin Castro smacked his first career leadoff homer, but two errors by Barney led to two unearned runs and helped the Brewers beat the Cubs, 5-2, in front of a sellout crowd of 41,661.
"Unfortunately me, and pretty much me, I didn't get the job done out there behind [Rodrigo Lopez] and didn't help him out," Barney said of the Cubs starter, who took the loss.
"I thought he pitched a great game," Barney said. "That's one of the best offensive clubs out there, and he held them down to two earned runs."
Castro, the National League hits leader, got things started on a positive note when he launched Randy Wolf's second pitch of the game over the wall in left-center. It was his eighth home run; Castro hit three last year.
With one out in the Chicago third, Barney was safe on an error by Wolf (11-8), who couldn't get his glove on Prince Fielder's throw. Barney then stole second and scored one out later on Jeff Baker's double for a 2-0 lead.
George Kottaras made it 2-1 with his third homer, a two-out shot in the Brewers' fourth off Lopez (4-5).
Then the fifth. Corey Hart singled to lead off, and Nyjer Morgan was safe on an error by Barney, who took the flip from Lopez on the sacrifice. Barney stepped on the bag twice, and he might have gotten the call by umpire Tom Hallion if he had stepped once in a convincing fashion.
Hart and Morgan moved up on a double steal, and Ryan Braun then lined a double off the top of the right-field wall. It wasn't high enough to be a home run, but the result was the same. Hart scored on the hit, while Barney's relay throw sailed past Aramis Ramirez at third, and both Morgan and Braun scored on the error for a 4-2 lead.
"I think it ended up being a Little League home run," Braun said. "But either way, same result for us."
"The first one was tough," Barney said of his errors. "I looked at the replay and I thought I was on there. I made a mistake of going back for [the bag]. Whether you're on there or not, when the play is moving quick, sometimes the umpire takes information from all different places. [Hallion is] not wrong at all. ... That's my mistake for going back at it.
"The second one was a lack of judgment. I saw Nyjer kind of doing his thing over there and thought I could make something happen, and unfortunately I didn't and put us in a little hole."
Getting Morgan on the bunt play would have changed the inning, possibly the outcome.
"I think Barney had him and went back [with his foot] to make sure," Cubs manager Mike Quade said. "That's tough for an umpire to take a look at. That would've helped minimize the damage for sure. And then an error on the relay throw, trying to do too much."
The Cubs dropped to 1-6 at Miller Park, and the Brewers maintained a 9 1/2-game lead in the National League Central. The miscues were Nos. 109 and 110 of the season for the Cubs, most in the Major Leagues.
"You make mistakes and you've got to try to play around them," Quade said. "[Barney] doesn't make many, but every so often those things happen. For Braun's extra-base hit and all the rest of it, we make the bunt play and we're in a lot better shape."
The Brewers swept the Cubs at Miller Park one month ago, and at that time, Jim Hendry was the general manager, Carlos Zambrano was in the rotation, and Chicago had a tough time scoring runs. Some things have changed -- Hendry was dismissed one week ago, and Zambrano is on the disqualified list for behaving badly -- but the Cubs are still struggling offensively against the Brewers. And errors don't help.
Lopez threw a season-high 101 pitches over six innings and gave up four runs -- two earned -- on four walks and five hits, including Braun's weird double.
"That was one of the few mistakes that Rodrigo made tonight," Wolf said of Braun's double off the Cubs right-hander. "I was sitting in the video room next to the dugout, and he was really hitting his spots in and out. He really made two mistakes -- one to George and one to Ryan there. It was good we got those big hits, because he was tough today."
Lopez said he was trying to get Braun to pull the ball because of the runners.
"The pitch was a little bit up, but he was thinking, 'Go opposite field,'" Lopez said. "Then there was the error on third, and that's the way it was. The pitch [to Braun] was where I wanted as far as location, but I missed a little up in the zone."
And the Brewers took advantage of the mistakes.
"You don't win championships without pitching and defense," Barney said. "We're going to get better and be more fundamentally sound. As our defense gets better, our pitching will get better. That's the way things work. There's a lot of room for improvement, and we're going to work really hard to get better and clean that stuff up."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter@CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.