PITTSBURGH -- As usual, the Brewers left their mojo on the other side of the Allegheny River.

They have exhausted every other explanation for the team's continued torment at PNC Park, a beautiful joint just across the river from downtown Pittsburgh that should be a pleasant place to visit.

It is more like a haunted house to the Brewers.

Their woes their continued on Monday, when starter Carlos Villanueva surrendered a costly home run and second baseman Rickie Weeks committed a costly error in the Brewers' 9-0 loss to the Pirates.

The Brewers fell to 1-4 in Pittsburgh this season and 19-41 since the stadium opened in 2001. Coupled with a Cubs win earlier Monday, they also fell back into a first-place tie in the National League Central.

"We've been taking care of series," said Villanueva, who took the loss. "And that's what we have to do now."

They will need some offense if they are going to win the series. A Milwaukee lineup that bashed six home runs in Sunday's win at Cincinnati was held scoreless on three hits over six innings by Pittsburgh starter Tony Armas (4-5), a right-hander who entered with a 6.49 ERA but has pitched better of late. Armas has worked six innings and surrendered three or fewer runs in each of his last three starts including Monday's.

"Armas was locating his pitches very well, executing his pitches and kept the ball down," Brewers manager Ned Yost said.

The Pirates' offense was even better. The unit leads the National League in runs scored since Aug. 1.

Making his second start since returning from Triple-A, Villanueva (7-4) stranded a runner at third base in the second inning and escaped a bases-loaded jam in the fourth. But the Pirates snapped the scoreless tie in the fifth, when Nyjer Morgan hit a ground-rule double off the chalk down the left-field line and Nate McLouth followed with a two-run home run that cleared the right-field seats and bounced into the river.

It was the 1,000th home run in the seven-year history of PNC Park and the 22nd to reach the river.

Villanueva struck out Freddy Sanchez and induced an Adam LaRoche groundout to escape further damage. Laynce Nix pinch-hit for Villanueva leading off the sixth.

"Definitely, I think I could have gone longer," Villanueva said. "But that decision is not up to me. We have a lot of guys in the 'pen. Of course, you are always going to be a little disappointed, as I told Ned, but I understand the decision to bring in a pinch-hitter that inning. If it was up to me, I would have stayed in the whole game."

Said Yost: "After the fifth inning ... if you're behind, you have to think about offense. The pitcher's spot came up in the sixth inning there. If the score was tied or we were ahead he probably would have hit and gone out for the sixth. I thought he threw the ball very well."

Reliever Matt Wise took over in the sixth and surrendered a trio of singles, but should have escaped with a scoreless inning when pinch-hitter Josh Phelps hit a double-play grounder to third base. But Weeks took the feed at second base and bounced his relay throw to first base for an error that allowed two Pirates runs to score.

"That was huge right there," Yost said. "You have to turn that right there. This time of year, you have to turn those."

Weeks said he got a clean grip of the baseball but "yanked" the throw.

"It happens," Weeks said.

Pittsburgh tacked on four runs in the seventh against Brian Shouse and Seth McClung and another run in the ninth against Greg Aquinio.

"It's evaluation time for them," Villanueva said of the free-swinging Pirates. "They don't have anything to play for, pennant-wise, but you certainly don't take them lightly. They have a pretty good team. They manufactured runs well today. You can't sleep on them."

The Brewers went to sleep Monday night dreaming of ways to fix their Pittsburgh jinx. They are tied with the Cubs atop the division at 73-70, and the Cardinals are three games back.

What is it about PNC Park that gives the Brewers fits?

"I can't speak for everybody else, but I'm not thinking about it," Villanueva said. "Today we just couldn't get anything going. We have a couple more days to work on it, and we'll be all right."

Said Weeks: "This team always has confidence. I don't know what it is here, but I don't think it's one thing. They just play their best baseball here against us. You have to hand it to their offense, I guess."

First baseman Pricne Fielder wasn't buying the "give them credit" sentiment.

"Right now, I don't care about credit," he said. "We have to win."