Dempster struck out five over seven shutout innings in the Cubs' 7-0 victory over the Dodgers in front of a season-high crowd of 41,153 at Wrigley Field.
Reed Johnson had three hits, including a solo homer and a run-scoring bunt single, Mike Fontenot smacked an RBI double and RBI triple, and Milton Bradley had three hits to back Dempster (4-3).
Cubs manager Lou Piniella said he pulled Dempster after 99 pitches because the right-hander has been battling a blister and the team didn't want to take any chances.
"We're watching it really carefully," Piniella said. "If we need a few more days between his next start, we can always put him at the tail end of the rotation. We'll see how he is on Tuesday."
Dempster is not expected to miss a start, and the Cubs could give him an extra day. His next turn would have been Thursday, but Carlos Zambrano returns from his six-game suspension that day. Sean Marshall, who is starting Sunday night, could go Friday and give Dempster an extra day if needed.
Dempster had kept the blister a secret all season.
"For some reason, I've been battling it most of the year and have tried to keep it quiet," Dempster said. "It's had its good days and its bad, and we did a good job in between starts of getting it to where I need to be and got me out before it flared up. Hopefully we can get past this and it doesn't flare up the rest of the season."
On Monday, Dempster gave up six runs on seven hits over four innings against Pittsburgh, throwing 94 pitches in that short outing. He held the Dodgers, who lead the National League in batting, to three hits and one walk.
"I like to believe Monday is the exception and not the norm," Dempster said. "I just try to put that behind me. You're going to have good starts and bad starts, and it's what you do in between that's important. I try to bounce back and have a good outing and I was able to do that today, and it's easy when the guys put up a bunch of runs like that."
The difference, Piniella said, was that Dempster not only had good stuff but good command on Saturday.
"When he's had a poor outing this year, it's never been his stuff, it's always been command," Piniella said. "Today he had it going."
In Game 1 of the 2008 National League Division Series between Chicago and Los Angeles, the Dodgers took a patient approach against Dempster, and he walked seven over 4 2/3 innings. On Saturday, he walked one and gave up three hits: a two-out double to Russell Martin in the second, a two-out single to Matt Kemp in the fifth and a one-out double to Andre Ethier in the seventh.
"You just execute a pitch at a time, and go from there and not worry about what the score is or who's on base," Dempster said. "I was able to do that today and establish fastball command, and when I do that, I can throw my other pitches.
"The nice part is we haven't been scoring a lot of runs, so for the guys to break out and score a bunch of runs is real big. That's important for our team. To see Milton get three hits, Reed come up with a big day and Fontenot, that's nice to see. Hopefully that's something to keep rolling. It's a lot of fun winning -- a lot more run than losing, that's for sure."
Fontenot hit his RBI double in the second, driving in Johnson, who had singled. In the third, the Cubs had runners at first and third with two outs when Johnson bunted toward third base. Eric Stults (4-2) recovered the ball, but fell and couldn't get a throw off. Ryan Theriot, the runner at third, easily scored on the squeeze play.
Stults walked Bobby Scales to open the fourth and Fontenot, the only left-handed bat in the Cubs' lineup, followed with a triple into right-center to put Chicago ahead, 3-0. Stults then exited, and two outs later, Theriot hit an RBI single off Guillermo Mota.
Fontenot, who will be the regular third baseman with Aramis Ramirez sidelined until early July, had been in a skid during the Cubs' last road trip in St. Louis. He's batting .450 (9-for-20) in his past seven games.
"It was good, especially against the lefty," Fontenot said of the game. "I've been working on a lot of things and it's progressing the last week or so. I have to keep it going."
The Cubs loaded the bases in the fifth against Jeff Weaver, who then walked Geovany Soto to force in a run. Another run scored when Scales grounded into a double play. Weaver also served up Johnson's third homer with one out in the seventh.
The game marked the first time the Dodgers have been shut out this season. They still boast the best record in baseball, but this was their most lopsided loss.
"We're trying to win against anybody right now and everyone, but it feels good to know we can put runs on the board against a good team like that," Fontenot said.
But Dempster didn't feel any extra satisfaction in beating the Dodgers after what they did to him and the Cubs last October.
"It just feels good to win a game in general," the righty said. "They are a very good team. For me, it was important to keep the leadoff guys off base. They run a lot and use their speed real well. [Keeping them off] allowed me to work a little quicker and things like that.
"Just going up there and winning any game is great, no matter who it's against. I was just glad to get one today."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.