CHICAGO | Not a single boo was heard for Alfonso Soriano Monday night -- and for good reason.

The Cubs are flying high again, this time into sole possession of first place in the National League Central with their fourth win in a row after their easy 12-3 victory over the San Diego Padres. One big reason is Soriano is leading the way -- in the leadoff spot.

His average and power production are climbing along with the restoration of his playing time and health. Soriano's two-run homer touched off a sixth-run fifth inning. Then the left fielder, who has seven hits in his past 14 at-bats, had a double and a run scored in a five-run sixth as the Cubs made it the easiest outing of the season for Carlos Zambrano (6-1).

Fresh from driving in the key two runs with a double Saturday against the Arizona Diamondbacks, Soriano got more lift with his fourth homer, off starter Randy Wolf (2-3).

"I feel very comfortable at home plate," Soriano said. "I'm swinging at strikes and being more patient at home plate. That's what I want to do to help the team win. I'm being more aggressive, but at the same time being selective at home plate. When I swing at strikes, I know I hit the ball very hard."

Soriano could be in one of his patented hot streaks. He hit 14 homers last September.

"He's starting to swing the bat," Cubs manager Lou Piniella said. "He hit that two-run homer to put us ahead after they scored. That's good to see."

Geovany Soto chipped in with a two-run single in the fifth. Aramis Ramirez and Mark DeRosa also had RBI singles in the fifth, and DeRosa would collect another RBI hit in the sixth.

After slumping on the recent road trip, Cubs hitters have come to life at home.

They have scored 25 runs in their past three games, zooming out as the majors' leading run-producing team with 223 overall.

Meanwhile, Zambrano won his fourth consecutive start. He trailed 2-1 after ex-Cub Jody Gerut's fifth-inning homer. But Soriano and Co. lowered the boom. Zambrano threw just 96 pitches (60 strikes) while walking only two in seven innings. He has walked just 16 (while allowing 53 hits) in 62 innings so far.

Always loving a chance to bat, the switch-hitting Zambrano also had a double and single.

"It's good to have one hit right-handed and one left-handed," he said. "Anything I can do for my team, running, pinch-hitting, pitch, play outfield."