PITTSBURGH — Pittsburgh starter Paul Maholm wasn't convinced he would make it out of the first inning Friday night, things were going so poorly.

Then again, things have been going so poorly for the White Sox that Maholm shouldn't have been concerned.

Maholm loaded the bases in the first and gave up a run, before shutting down Chicago over the next six innings in a 4-2 victory.

"After the first few batters, I didn't know how long I was going to be in there, because it was just one of those things where the stuff wasn't going where I wanted it to," Maholm said. "For some reason, it just clicked, and I went from there."

Maholm (3-8) scattered eight baserunners while throwing 108 pitches — he allowed three hits, walked three batters and hit two — as the Pirates won for only the fourth time in his 14 starts this season.

Jose Bautista and Xavier Nady each drove in two runs for the Pirates, who have won three of four during a six-game interleague homestand. Chicago has lost nine of its last 10.

"It was a very well-pitched game by Paul Maholm," Pittsburgh manager Jim Tracy said. "He had some trouble locating and settling in, but he did a nice job in the first inning where they got just the run, and once he got himself going I think the big key was the sinker and the location of it."

After two walks and a Jermaine Dye single to left, A.J. Pierzynski's sacrifice fly to center scored Andy Gonzalez in the first. Maholm dazzled after that to win for the first time in six decisions.

"I was happy when I came out after the first having only given up one run, because it could have been a lot worse," said Maholm, whose only other win at home this season came April 24. "I told myself when I got into the dugout that that was all they were getting."

Shawn Chacon, in his first outing since being removed from the starting rotation after a poor start Sunday at Yankee Stadium, pitched a perfect eighth for the Pirates.

Matt Capps loaded the bases in the ninth, then walked Alex Cintron to score Pierzynski and make it 4-2. But Capps got Gonzalez to ground out for his fourth save.