CHICAGO(AP) Drawing on his previous Wrigley Field experience, Charlie Morton knew exactly what not to do.

Don't fall behind batters, don't pitch timidly, don't panic. And this time, he didn't.

Seven weeks after getting lit up for 10 runs by the Cubs, Morton pitched a four-hitter as the Pittsburgh Pirates defeated Chicago 4-0 Wednesday in the first game of a doubleheader.

''I try not to put so much emphasis on one game,'' he said of his performance in the 17-2 loss on Aug. 14. ''But it's a big step in the sense that, yeah, I came here and gave up 10 runs in an inning.

''This time ... I was throwing pretty much everything for strikes, more than I have been. Just being more aggressive with my pitches.''

Morton (5-9), a 25-year-old right-hander who hadn't pitched more than seven innings in a game, also set a career high with eight strikeouts. Acquired in the June 3 trade that sent Nate McLouth to Atlanta, he walked three and hit two batters. Ryan Theriot had three of the Cubs' hits, including two infield singles.

''To pitch a complete-game shutout, obviously you've got some things going on. He used his off-speed pitches very well and he didn't get behind very often,'' Pirates manager John Russell said. ''You take away the start he had here, and his numbers have been pretty good.''

Morton, who had a 3.66 ERA in his other 17 starts, was supported Wednesday by four first-inning runs against Cubs ace Ted Lilly .

Lilly (12-9) allowed five hits in seven innings and retired 19 of the last 21 batters he faced but still suffered only his second home loss this season. The Cubs' lone All-Star Game representative finished with a team-best 3.10 ERA but recorded his fewest victories since 2005, when he had 10 for Toronto.

Though manager Lou Piniella called Lilly ''our best pitcher,'' the left-hander said the season was unsatisfying because the Cubs failed to win a third consecutive NL Central title.

''One (reason) I was brought here was to try to get this team to the postseason and win some postseason games,'' said Lilly, who in 2007 lost his only playoff start with the team. ''I don't really feel I've met expectations at this point. Maybe next year will be different.''

Lilly walked two of the game's first three batters and gave up a single to Lastings Milledge , loading the bases. Steve Pearce then grounded to second baseman Andres Blanco , who shoveled to shortstop Theriot for the inning's second out.

As Theriot came off the base to his left, Milledge slid hard and kicked his legs sideways, knocking the shortstop to the ground as a run scored. Milledge was able to reach the bag with his arms, so he wasn't called for leaving the baseline, but fans still booed him the rest of the game.

''It was a clean play,'' Theriot said. ''Take guys out ... that's how you play the game. I'd do the same thing.''

Said Milledge: ''A lot of us are playing for spots next year. We can't afford to back off. I play the game hard.''

Jason Jaramillo followed with a two-run double to make it 3-0 and Brian Bixler singled home a run on the next pitch.

NOTES: Because it was a makeup for an Aug. 16 rainout, the actual crowd was small. But the paid attendance of 34,362 put the Cubs over the 3 million mark for the sixth straight season. ... The Pirates had been 3-15 at Wrigley dating back to Sept. 21, 2007. ... Pittsburgh pitchers have allowed only one home run in the last nine games. ... Cubs 3B Jeff Baker batted third for the first time since Chicago acquired him from Colorado on July 2. He went 0 for 4 but is still hitting .307 with the Cubs. ... Zach Duke had the Pirates' only other shutout this year.