CHICAGO - Alfonso Soriano's warming up, even if the weather isn't. He looked like his old self Saturday and hopes he's put his early struggles behind him.

The Cubs star had four hits, including a go-ahead double in a six-run seventh inning and showed some flair on the bases to help Chicago beat the Arizona Diamondbacks 7-2.

"I feel very comfortable now at home plate. My hands stayed back a little more now and I wait for the ball," Soriano said. "I'm glad I have a big day, more important that we won this game."

Soriano's 4-for-5 performance raised his average from .191 to .223. And slowed earlier this season by a calf injury that landed him the on the disabled list, he twice raced home and scored with good slides to send the largest crowd of the season at Wrigley Field (41,597) into a tizzy.

"It happened twice today. I don't like close plays because the catchers are very strong. I think I got safe on both plays," he said.

Kosuke Fukudome's first homer since opening day capped the seventh-inning rally as the Cubs won their second straight against the team that swept them in the first round of the playoffs in October.

After a strong performance by Diamondbacks' rookie Max Scherzer, the Cubs trailed 2-1 headed into the seventh when they got to Arizona reliever Chad Qualls (0-4), whose ERA jumped from 0.93 to 2.75 when he gave up four runs and four hits in one-third of an inning.

It was especially disappointing for Qualls after the way Scherzer pitched in just his second major league start.

"It's unbelievable to come out here in Wrigley Field and the environment and do as good as he did," Qualls said, adding he made one bad pitch to Soriano.

"I threw a bunch of good pitches to Soriano. The one mistake I made on him, he hit into the gap."

Mark DeRosa had a leadoff single, Reed Johnson sacrificed and pinch-hitter Daryle Ward dropped an RBI single down the left-field line to tie the score.

Pinch-runner Jason Marquis moved to second on a wild pitch and scored on Soriano's double to left center that made it 3-2. When Ryan Theriot singled up the middle, Soriano -- obviously not at full speed -- was still sent home and slid under catcher Chris Snyder after a strong throw from center fielder Chris Young.

"I was a little scared because it is a little cold and I used my legs a lot today," Soriano said of the 47-degree day. "I have to play a little more and be comfortable with my leg."

Aramis Ramirez added an RBI single off Brandon Medders before Fukudome hit his second homer of the season.

Cubs starter Ryan Dempster gave up only three hits and two runs in six innings. Scott Eyre (1-0), who just came off the disabled list Friday, pitched the seventh.