Lohse worked seven strong innings with less than his best and the St. Louis Cardinals' slumbering offense opened with three quick runs against Dempster in a 4-1 victory over the Chicago Cubs on Friday night.
"You get behind the 8-ball really quick," Dempster said. "After that, I feel like I settled down and made some pitches -- other than Matt Holliday hitting one off the Arch."
Matt Holliday added a home run in the third inning that ESPN's Home Run Tracker calculated at 438 feet.
"Honestly, I didn't want to watch it because I have a lot of respect for Ryan," Holliday said. "I got it good."
Lohse (10-2) won his fourth straight decision over five starts to complement a lineup that topped three runs for the first time in 12 games. The defending World Series champions found an unlikely victim in Dempster (5-4) after totaling 15 runs and going 8-for-51 (.157) with runners scoring position on a 1-5 trip that left them five games back in the NL Central to start the day.
"We were fortunate to have him make some mistakes early, get us a lead like that," Lohse said. "I wasn't counting on him giving up any more after that.
"It's always tough when you know someone like that is on the other side."
Dempster hadn't allowed a run since May 30 while winning five straight starts and entered with a major league-best 1.86 ERA before running into immediate trouble, giving up four straight singles in a span of six pitches with one out. Carlos Beltran and Yadier Molina each had an RBI single and Lance Berkman drove in a run with a groundout.
"I know he's been pitching great and all that, but our plan was to try to get on base and score early," Beltran said. "Offensively, we have wasted a lot of opportunities, but right now we're focusing on trying to do better."
Dempster allowed four runs in six innings while under heavy scrutiny from several teams looking to make a deal before the trade deadline. The streak was the majors' longest since the Phillies' Cliff Lee had a 34-inning run last year, and it was the Cubs' longest since Ken Holtzman also had a 33-inning streak in 1969.
"It was a lot of fun to go up there and do that," Dempster said. "It's a humbling thing to try and take something that you dream about doing. But actually doing it is another thing. I'm very proud of that."
Dempster said trade rumors have nothing to do with what happened in the first inning.
"Not at all," he said. "Really, it was just about a span of six pitches, and next thing you know it was 3-0.
"Sometimes they could have popped those pitches up, grounded them out or flown out. But they didn't. They hit them really hard and got some base hits."
Seven straight Cardinals were retired before Holliday's one-out clout in the third that soared past Big Mac Land in left field. It was his 15th of the year and first since he connected in consecutive games July 2-3 against the Rockies.
The Cubs lost for the 11th time in their last 15 games in St. Louis.
Manager Mike Matheny juggled the lineup with Skip Schumaker, who entered a .431 career hitter against Dempster, at the top and Furcal dropped to eighth for the first time this season. Schumaker took a called third strike to open the first and was 1 for 4 while Furcal had two hits.
Lohse has won 13 of his last 15 starts dating to last season, according to STATS LLC. He worked seven or more innings for the seventh time in eight starts, allowing a run on six hits with four strikeouts, all but one looking.
"It was one of those days that was kind of just a low-energy day," Lohse said. "I knew warming up I was going to have to grind through it and make some pitches, and that's pretty much what I did."
The Cubs opened the second with a walk by Bryan LaHair, a single by Steve Clevenger and a sacrifice fly by Darwin Barney. They had only two runners in scoring position against Lohse, and were a collective 2 for 15 with men on.
Jason Motte worked a perfect ninth for his 21st save in 25 chances, and first in three chances against the Cubs. He needed just six pitches.
"I got 'em," Motte said. "That's all that matters."
Molina has 11 RBIs against the Cubs this year and 21 the last two seasons, both of them best by an opponent in the majors. ... Berkman doubled in the third for his first hit in 11 at-bats since being activated from the 15-day disabled list from a knee injury to start the second half. ... Dempster entered with an 0.95 ERA in seven road starts, surrendering five runs in 47 1/3 innings.
Information from The Associated Press was used in this report.