PITTSBURGH — The Chicago Cubs picked a bad night to run into a pitcher who almost always gives them problems.

Tom Gorzelanny allowed one run over seven effective innings and Jack Wilson homered while driving in three runs as the Pittsburgh Pirates beat Chicago 6-1 Friday night, the slumping Cubs' fourth loss in five games.

Gorzelanny (14-7) has been tough on the Cubs before, giving up two earned runs in 22 innings over three career starts, a 0.82 ERA. But this one especially hurt the Cubs, who couldn't bounce back from a 7-4 loss Thursday in which the Dodgers scored four runs in the ninth inning against closer Ryan Dempster.

"Right now, every game counts. We've got 22 games left," the Cubs' Alfonso Soriano said. "We are tied for first place, so hopefully we'll play better tomorrow."

Chicago, beginning a closing stretch in which it plays 16 of the final 23 away from Wrigley Field, remained tied with Milwaukee for the NL Central lead after the Brewers lost at Cincinnati 11-4. St. Louis stayed one game back.

"I don't know if it was the slump of the team or if Gorzelanny did good," said Soriano, who went 0-for-5 a day after homering twice.

The Cubs started the road trip as the only division team with a winning record on the road, 33-32, but couldn't do much as Gorzelanny limited them to six hits, striking out three and walking two. The Cubs didn't score until they were down 6-0 in the seventh, when Geovany Soto doubled and scored on pinch-hitter Ronny Cedeno's RBI single.

Gorzelanny kept up a strong run of late-season pitching by winning for the fifth time in six decisions. His 14 victories are the most by a Pittsburgh left-hander since Denny Neagle was 14-6 in 1996.

"Those are good numbers," said Gorzelanny, who had only two career victories before this season. "I'm trying to add on every time I go out there and finish the season right."

With a runner on in the sixth, Wilson hit his ninth homer, a drive into the left-field bleachers. Wilson went 3-for-4 and has 14 hits in 20 at-bats (.700) over four games.

"It's just like when you go into a bad slump. You don't always know why you're doing it but you hope to keep it going," Wilson said.