CHICAGO -- Lou Piniella predicted that once the Cubs hit one home run, they would start hitting them in bunches.

He was right.

Derrek Lee, Angel Pagan and Ryan Theriot each homered on Sunday, one day after Alfonso Soriano ended the team's 10-game homerless drought, to give the Cubs a 7-6 victory over the Astros and complete a three-game sweep at Wrigley Field. Chicago fell behind, 5-0, early on, but rallied to boost its record to a season-high four games over .500.

"We're playing great," Lee said. "We knew we had a good team, but now we have that confidence to go along with it. There was a time when we got down like that, we might not have been sure we could come back. Now we really feel like we can really come back and win the game."

The comeback began in the second when the Cubs sent 10 batters to the plate. Mark DeRosa hit a one-out double and scored on Geovany Soto's single. Pagan then hit a two-run homer on the first pitch from Wandy Rodriguez to close the gap to 5-3.

Cubs starter Jason Marquis and Theriot singled before Mike Fontenot grounded back to Rodriguez for what could have been an inning-ending double play. But Rodriguez dropped the ball and was only able to get Fontenot out at first. Lee belted a three-run homer, his first since June 3, to put the Cubs ahead, 6-5.

"It's been a long time," Lee said. "It felt good, plus it gave us the lead, put us back in the game."

The Astros leveled the score in the third on a solo home run by Mike Lamb. Theriot had the eventual game-winning hit on a solo shot of his own in the fourth to make it 7-6.

"We have a pretty exciting offense, and I don't think anybody in the dugout ever felt we were out of the game," Theriot said. "It's good to be able to contribute and help the team win, whether it be a base-hit single or a home run."

The left-handed Rodriguez (6-8) took the loss for the Astros, partly as a result of Piniella adjusting his batting order to improve his team's 8-14 record against lefties. Soriano was taken out of the leadoff position for only the eighth time this season, and instead hit fifth. Theriot was 2-for-5 in the leadoff position. So was Piniella happy with the adjustments?

"We scored seven runs," Piniella said. "That's a measure. You've got to judge it as a success. Seven runs is good production out of any lineup."

The Cubs are 15-4 in their last 19 games, and their 25-12 record since June 3 is the best in the National League.

Michael Wuertz (2-2) got the win after combining with Scott Eyre, Carlos Marmol, Will Ohman and Bob Howry to throw five shutout innings out of the bullpen. Howry picked up his fifth save and the bullpen's seventh since closer Ryan Dempster went on the disabled list June 23.

Wuertz entered the game with two outs and runners on second and third in the seventh. He walked pinch-hitter Morgan Ensberg to load the bases before striking out Chris Burke on a low 3-2 slider to end the inning.

"I stuck with it the whole at-bat to him, and fortunately he chased it," Wuertz said. "In situations like that, you've got to go with your strength, and that's what I did. Our guys battled to get us back in the game, and you just have to do the same when you're out of the bullpen."

Marquis lasted four innings and gave up all six runs to the Astros. Despite recording only one win in his last 12 starts, Marquis did not think any major changes needed to be made.

"I think it's a slight thing more than anything," Marquis said. "Mixing speeds is a huge part of it. I've got to get more confident in throwing off-speed pitches for strikes."

Marquis has not gone past the fifth inning in his last two starts and is trying to avoid a repeat of his 3-10 record in the second half last year.

"I know that when he gets ground balls and throws sinkers, the ball's sinking and he's got more movement on it, he has a much easier time of it," Piniella said. "When he doesn't, he gets hit more."

Marmol, who had been used more as a late-inning pitcher, came on with two outs in the fifth.

"Sometimes you've got to save the game in the fifth or the sixth inning," Piniella said. "If not, there's nothing to save later on."

The sweep was the Cubs' fifth of the year and first over Houston at Wrigley Field since May 18-20, 1984.

"The club is gaining confidence, that's important," Piniella said. "We fell behind 5-0 today, and these kids came right back with six runs in the second inning as it was, and finally we scored the seventh in the fourth, and our pitching comes in and does the rest, with the help of good defensive plays.

"They're playing with confidence," Piniella added, "and confidence is a good thing."