The Chicago Cubs ace survived six choppy innings -- and one long homer from Lee -- to lead the Cubs to a 5-3 victory on Monday night and send the reeling Pirates to their fourth straight loss.
Zambrano (8-6) picked up his 13th career win over Pittsburgh, tied with Aaron Harang for second-most among active pitchers. The veteran right-hander struck out five and walked three while giving up seven hits. Carlos Marmol pitched a perfect ninth to collect his 21st save.
"I did what I was supposed to do," Zambrano said.
And did what he's always done against the Pirates, particularly at PNC Park. Zambrano improved to 8-1 all-time at the hitter-friendly yard and shook off a shaky July with his best outing -- by the numbers anyway -- since early June.
He had trouble with his command, throwing just 66 of his 114 pitches for strikes, but the Pirates failed to take advantage, leaving seven runners on base.
"Personally I feel like I've been throwing the ball good," Zambrano said. "I was able to battle and pitch six innings."
Lee ended up homering twice less than 48 hours after being acquired from Baltimore, but it wasn't enough as the Pirates lost for the sixth time in eight games to slip further behind Milwaukee in the National League Central race.
The 35-year-old Lee spent six seasons in Chicago but swears he doesn't have inside knowledge of Zambrano. He added he didn't feel strange stepping in the box against Zambrano, noting he did the same last year after the Cubs shipped him to Atlanta.
Maybe, but his appearance in the batter's box had an adverse affect on Chicago manager Mike Quade.
"It was sickening is what it was -- weird has got nothing to do with it," Quade said. "We've all watched him long enough and have so much respect for him, we know he's capable of that. Just wish he'd save that stuff for someone else."
The Pirates, in first-place two weeks ago, are now just one game above .500 (54-53), the closest they've been to the break-even mark in a month.
"It's like when you're on an airplane and the captain says, 'Buckle your seatbelt, we're going to hit some turbulence,'" said Pittsburgh manager Clint Hurdle. "We've hit some turbulence. That's all it is. No one said it would be easy."
Lee certainly made it look easy. Brought in along with Ryan Ludwick to give one of baseball's weakest offenses a spark, Lee did just that. He tied the game at 1 in the fourth with a lengthy homer to left and pulled the Pirates to 4-3 in the eighth on a two-run shot to center off reliever Kerry Wood.
"It was nice to get some hits and contribute," Lee said. "Unfortunately they got the win so we turn the page and get ready to go tomorrow."
Lee became the first Pirate to hit two homers in his Pittsburgh debut since Shawon Dunston did it against Cleveland on Sept. 2, 1997.
Starlin Castro had three hits for Chicago, which has won two straight after dropping five in a row.
Ludwick, picked up by the Pirates just before the trade deadline, went 0 for 3 with a walk on a day that began with a cross-country flight from San Diego. He didn't arrive at the ballpark until 5 p.m. and headed straight to the kitchen to eat rather than squeeze in some batting practice.
Paul Maholm (6-11) surrendered four runs on six hits in six innings, striking out three and walking three. He had little trouble through the first five innings, allowing just one run on Jeff Baker's sacrifice fly but ran into trouble after reaching first on a fielder's choice in the bottom of the fifth.
Teammate Garrett Jones slashed a line drive right at Maholm as the pitcher led off first and the ball drilled Maholm in the right (non-throwing) shoulder. It did more than just end the inning, it seemed to end Maholm's effectiveness even if Maholm said the hit didn't bother him.
Castro and Baker hit consecutive singles to start the sixth and Geovany Soto followed with a double down the left-field line. Maholm intentionally walked Marlon Byrd to load the bases with no out. Alfonso Soriano grounded to short but beat out the attempted double-play throw as Baker scored. Carlos Pena added a sacrifice fly to push Chicago's lead to three.
"They bunched some hits together that inning and pushed a few across," Maholm said.
That was enough for the Cubs, who won their second straight following a five-game skid.
Neil Walker and Pedro Alvarez had two hits apiece for Pittsburgh. But the Pirates left seven runners on base and again failed to get the clutch hit they needed to try and stay within striking distance in the National League Central.
"We've just got to get over it and come back tomorrow and do what we've been doing all year, grinding it out for nine innings and winning," Maholm said.
The Pirates are now 12-43 in games in which they scored four runs or less. ... Philadelphia pitcher Roy Oswalt's 15 career wins is the most by an active pitcher against the Pirates. ... Chicago's nine wins over the Pirates the last two years are the fewest of any NL Central club. ... The Cubs are 48-36 all-time at PNC Park.