CHICAGO -- It was finger-numbing cold at Wrigley Field Monday night, with a game-time temperature at 41 degrees, but that didn't stop the red-hot Cubs.

Alfonso Soriano hit a two-run homer, and Geovany Soto smacked a two-run single to highlight a six-run fifth inning and back Carlos Zambrano as the Cubs beat the San Diego Padres, 12-3, to win their fourth straight game.

Chicago, which also scored five runs in the sixth, now leads the National League Central and is first in the Major Leagues in runs scored with 223. Zambrano helped the cause by collecting two hits, one from each side of the plate. Wasn't he cold?

"It's OK for me -- I'm from Alaska," Zambrano said.

Actually, he's not.

"It's tough," Zambrano admitted. "I'm from South America, Venezuela, and it's not this cold, not even close. We have to make the adjustment. You have to go out there and not worry about the cold factor. You try to hit your spot and try to do the best you can to keep the inning quick."

Zambrano (6-1) started the game in short sleeves, then switched after the third inning to a long-sleeve top under his jersey. It wasn't the cold, but because of a scab on his right elbow from a slide last week in Cincinnati.

The right-hander, off to the best start in his career, gave up six hits and walked two while striking out five over seven innings for his fifth straight win. He's now 4-0 with a 1.96 ERA at home. He also had a leadoff double in the fifth and a single in the seventh.

"Anything I can do for my team, I'll do it -- running, pinch-hitter, pitch, play outfield," Zambrano said.

Despite the offensive surge, the Cubs may be looking for more help. They are reportedly considering veteran Jim Edmonds, 37, who was released Friday by the Padres after hitting .178 in 26 games. He is expected to clear waivers on Wednesday.

"He's been on a lot of winning ballclubs, he's won a championship, he's been a mainstay in the middle of the lineup for a great team for a long time," Chicago's Mark DeRosa said. "I know one thing this team lacks is left-handed bats. You read about that constantly. If he can come and help us out, bring him on."

The Cubs are doing pretty well with the current group. The Padres had taken a 2-1 lead in the fifth on Jody Gerut's solo homer, his first since May 24, 2005. The lead was shortlived.

Chicago sent 10 batters to the plate in the fifth, and Zambrano, who loves to hit, got two at-bats. He doubled to open the inning, and Soriano followed with his fourth homer off a 1-2 pitch from Randy Wolf (2-3) that landed in the front row of the bleachers in left-center. Ryan Theriot walked and advanced on Derrek Lee's single before scoring on Aramis Ramirez's single to make it 4-2.

Kosuke Fukudome walked to load the bases for Soto, who singled to center, driving in two. DeRosa added an RBI single for a 7-2 lead.

The Cubs added five runs in the sixth. They loaded the bases against Sean Henn, who walked Fukudome to force in a run. One out later, DeRosa bounced the ball to third baseman Kevin Kouzmanoff, who was a step late getting the runner at third, then threw the ball away trying for the force at first. Three runs scored, two on the error, and Reed Johnson followed with an RBI single to make it 12-2.

Soriano is batting .310 this month, and notched multiple extra-base hits for the first time this season.

"You knew it was a matter of time," DeRosa said of Soriano. "The guy's one of the best players in the game for a reason. He did the same thing last year. He'll end up with his 30 homers and be one of the most exciting players in the game."

"I feel more comfortable at home plate, and I'm being more aggressive, but at the same time, I'm being selective," Soriano said. "When I swing at strikes, I know I hit the ball very hard, and that's what I'm trying to do is swing at strikes."

It seems like everyone in the lineup is doing that, at least at home. The Cubs are batting .316 at Wrigley, .246 on the road.

"We have good hitters, and good hitters have good at-bats," Lee said. "Guys like Fukudome join the lineup, he's a professional hitter. Soto comes in and he's done a great job. Theriot has a couple years experience under his belt now. We have a lineup of good hitters, and good hitters put together good at-bats."

Zambrano definitely benefited.

"We've been swinging the bats very well at home," Cubs manager Lou Piniella said. "When you do that, it makes it much easier on your pitching."