Zambrano won for the first time since July 22 by limiting the slumping-again Pirates to two runs over six innings, and the Cubs finished off a three-game sweep by beating Pittsburgh 8-5 on Wednesday.
Playing before a sparse crowd that was announced at 10,899 but looked -- and sounded -- like it was much smaller, the Cubs won their sixth in a row against the Pirates, who completed a 1-5 homestand.
The first two games of the series featured the Pirates setting a major league record on Monday by assuring themselves of a 17th consecutive losing season and the Cubs tying a record with eight successive hits to begin Tuesday night's game.
No streaks in this one -- just a lively conversation as Piniella replaced Zambrano after the right-hander warmed up to start the seventh. When the Pirates brought up the left-handed hitting Ramon Vazquez, Piniella decided to bring in left-hander John Grabow.
The hard part for Piniella was telling Zambrano, who clearly didn't want to leave. Zambrano and Piniella had an animated talk on the mound that continued in the dugout.
"I wanted to pitch another inning but it's Lou's decision," said Zambrano, who struck out eight and gave up five hits. "You saw the replay, everybody thought I was arguing but we were just talking. Every time Lou talks it seems like he's mad, the way he moves his hands, but he's not. He's very professional."
Zambrano was sidelined recently for three weeks by back spasms, and Piniella was satisfied with his 98-pitch outing.
"Like I told him, let's get built (up), let's get you stronger and stronger," Piniella said. "That was the conversation on the mound. I told him, `Next time if you want, we won't warm anybody up and we'll let you pitch nine innings.' "
Zambrano (8-6) was 0-2 in his previous five starts and hadn't won since beating the Phillies 10-5 on July 22. But he's usually good for a win against the Pirates, going 4-0 as the Cubs have won seven of his last eight starts against them. Zambrano is 7-1 in 13 career starts in PNC Park.
It may be too late to save the Cubs' season, but Zambrano still has time to get something out of a second half of the season he calls "horrible."
"Professionally, for me, it's been miserable," he said. "I think I only have to win. This is my first year I've been so poor in the second half. (I'm) just trying to finish the season strong."
Again, the Pirates (54-84) aren't.
Now 30 games under .500, they are careening toward a fifth consecutive 90-loss season and their seventh since 2000. They have lost 12 of 13, the second time they've done that while going 9-26 since Aug. 2.
Hart, dealt to the Pirates by Chicago in the Tom Gorzelanny-John Grabow trade in July, walked six while giving up four runs and six hits in five innings. After going 3-1 with the Cubs, he is 1-5 in seven starts with Pittsburgh as he struggles to make mechanical adjustments between starts.
"I'm going to stay positive," Hart said. "I've gone through stretches like this before, in the minor leagues, and came out on top and I'm not going to let it beat me."
Carlos Marmol pitched the ninth inning for his 11th save in 15 opportunities.
Karstens, out since Aug. 25 with a lower back strain, was reinstated from the 15-day disabled list. .. Cubs LF Bobby Scales collided with a wall in foul territory trying to run down Brandon Moss' fly ball in the fifth, but stayed in the game. ... Pirates 2B Delwyn Young is hitless in 21 at-bats.