CHICAGO -- If the Cubs are going to get back in the race in the National League Central, they will have to play .700 ball the rest of the way, pitcher Ryan Dempster said.

And losing the way they did Sunday in a 4-3, 11-inning loss to the first-place St. Louis Cardinals isn't going to help.

Felipe Lopez hit a solo homer with two outs in the 11th to boost the Cardinals back into first in the National League Central and avoid a sweep in front of 41,406 blue- and red-clad fans, the largest crowd at Wrigley Field this season.

Lopez connected on a 3-2 pitch from Brian Schlitter (0-1), one of four rookies in the Cubs' bullpen.

"You put runs on the board and you don't worry about [the rookies]," Cubs manager Lou Piniella said.

The Cubs have not topped .500 this season. Playing .700 is tough to imagine.

"You've got to keep fighting and trying to win as many games as possible," said Dempster, lifted after seven innings. "We won a series again. That's what you have to do -- you have to play .700 baseball."

"It's been done," Chicago center fielder Marlon Byrd said, "and that's what we plan on doing. We have a very positive team. That's how I look at it. We just plan on going out and winning."

Both teams had chances. The Cardinals loaded the bases with one out in the 10th against Schlitter and the Cubs got a break when Matt Holliday hesitated on Skip Schumaker's single, thinking Byrd would catch the ball. Byrd had thrown Schumaker out at home in the sixth.

Chicago loaded the bases in the 10th, taking advantage of an error by Schumaker, but Byrd was called out on strikes. The Cubs finished the homestand, 6-4.

"It's not encouraging," Byrd said. "I wanted to win this game tonight. We had our chances. I had a good shot and I didn't get the job done."

"We're winning with more consistency," Piniella said. "The way I look at this homestand here, I thought we should've been 9-1 if we hit a little bit. The games we hit in, we won and the games we didn't, we lost."

St. Louis took a 2-0 lead in the second on RBI singles by Schumaker and Brendan Ryan. Derrek Lee doubled to lead off the Cubs' fourth and scored one out later on Byrd's single to close to 2-1.

Geovany Soto drew a walk to open the Chicago fifth, although Chris Carpenter wasn't happy with home-plate umpire Bob Davidson's call, and then scored on Ryan Theriot's triple past a diving Jay in center. Two outs later, rookie Starlin Castro singled to score Theriot.

But Albert Pujols tied the game at 3 with a leadoff homer in the Cardinals sixth, his 23rd, off a 3-1 pitch from Dempster.

"What he does is, the offense has been struggling, so he's expanded his strike zone," Cardinals manager Tony La Russa said of Pujols. "If he was thinking about himself, he'd maybe be hitting 20 points higher, but he wouldn't have all the production. He is such a great, winning player."

Two outs later, Schumaker doubled and Yadier Molina was intentionally walked so Dempster could face Carpenter. The pitcher singled to center, but Byrd threw Schumaker out at the plate to end the inning.

"The guys gave me a lead and unfortunately I handed it right back," Dempster said.

Castro made a run-saving rundown in the first, when he gunned down Ryan Ludwick at home. That and Byrd's play were quality web gems.

"That's the kind of stuff that wins you ballgames," Dempster said of the two plays. "That was a huge throw by Marlon, especially with two out and the guy's going on contact and he makes the great throw. Castro made an unbelievable play. If you look at the replay he's running full sprint toward first. It shows you the athleticism and what a special player he'll be."

But it wasn't enough.

"You want [a sweep] -- we were in position to do it," Piniella said. "We won a series, but when you're behind like we are, it would've been much nicer to win all three."