Roy Halladay crossed one more item off his to-do list, and Placido Polanco adapted well to a new place in the batting order on Friday night.

Halladay had never beaten the Chicago Cubs until the Phillies' 7-5 victory in front of the 157th consecutive regular-season sellout crowd at Citizens Bank Park.

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Polanco had not batted fifth this season until manager Charlie Manuel penciled him in at that spot on Friday. If one night is any indication, he may not be moving.

Polanco's seventh-inning grand slam off Carlos Zambrano gave the Phillies a 7-0 lead. It was his 100th career home run and third career slam.

"When I am in the batter's box, I don't think I'm hitting fifth or second; I try to do my job," Polanco said.

With the bases loaded, Polanco was looking to drive the ball.

"I tried to be aggressive," he said. "He [Zambrano] is a great pitcher and may only give you one pitch to hit in the at-bat."

Halladay had been 0-3 with a 4.50 earned run average lifetime against the Cubs. Now the only teams he has never beaten are the San Francisco Giants and the Phillies. He pitched seven shutout innings, allowing six hits, before the bullpen made things interesting in the eighth inning.

Halladay (9-3) struck out nine and walked none. He said he was ready to pitch in the eighth until Polanco hit his slam. So when Manuel gave him the rest of the night off, Halladay didn't lobby to return.

"Most starters, we've been grinding, and when you get a lead like that, I definitely understand," he said. "It's not the first time I've ever seen it. I was fine with it."

Of course, Halladay likes to finish what he starts.

"You want to go as far as you can, but it makes sense to me," he said. "There is a long ways to go, and any time you can save a few [innings], it will pay off down the road."

The Phillies got a first-inning run on Ryan Howard's RBI groundout and two more in the second on a homer by Domonic Brown.

And then Polanco seemingly broke it open until the bullpen almost gave it back.

Even Manuel doesn't know how long he will keep Polanco batting fifth, but after Friday's game, it may be more than a temporary move.

"He has a chance to stay there a while," the manager said. "He will be there tomorrow."

Staked to the 7-0 lead, the Phillies bullpen struggled mightily. Jose Contreras allowed four runs in just a third of an inning in relief of Halladay. J.C. Romero faced three batters, issuing a walk, an RBI single to Geovany Soto, and a two-run single to Lou Montanez.

Michael Stutes took over and recorded a strikeout before ending the eighth by getting Kosuke Fukudome to fly to left.

"I am just happy to be put in a situation like this, and it is something that gives you confidence," Stutes said.

Darwin Barney opened the ninth with a single against Stutes. Starlin Castro then struck out, but the ball got by catcher Carlos Ruiz, who quickly retrieved it and gunned down Barney at second for the second out. Antonio Bastardo struck out Carlos Pena to earn the save.

Due to a heavy workload recently, closer Ryan Madson was given the night off. Manuel expects him to be available if needed Saturday.

Contact staff writer Marc Narducci at 856-779-3225, mnarducci@phillynews.com, or @sjnard on Twitter