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After three miserable games against their crosstown rivals, there wasn't much left for the White Sox to say.

"We just got beat in all facets of the game," White Sox first baseman Paul Konerko said. "They were just the better team in every area."

Cubs pitcher Travis Wood hit a grand slam off Jake Peavy and the White Sox lost 8-3 on Thursday.

It was the first time the White Sox lost the Crosstown Cup since 2007. There is still one game to be played in the series — Tuesday's game was rained out and hasn't been rescheduled.

The White Sox had won five of their past six coming into the series and had reached .500 (24-24) for the first time since April 8. Then they got outscored by the Cubs 24-6.

Wood's homer was one of three by the Cubs on Thursday. His RBIs gave Cubs pitchers 19 RBI this month, the most by pitching staff since the Detroit Tigers in 1940 and the most ever by an NL staff.

"Any time you have three games like this at any point it's discouraging," White Sox manager Robin Ventura said. "You know, again, you've got to regroup and go.

"We've show that we can play a lot better than this and we're going to have to prove it again."

With the winds blowing out at Wrigley Field, Nate Schierholtz and Luis Valbuena each hit their sixth home runs of the year. Chicago has won four straight overall.

Wood (5-3) broke open the game with his fifth career home run and second this year in the fourth inning with the Cubs leading 2-1.

"Woody can flat-out hit," Cubs manager Dale Sveum said. "He hits any fastball. They've (pitchers hitting) all been a big key to these wins.

"They're not just getting a single and driving a run in. They're getting two-run doubles and home runs, and we're able to put games away."

Welington Castillo and Valbuena started the fourth inning with singles and Peavy hit Darwin Barney before Wood's home run. It was the first grand slam by a Cubs pitcher since Jason Marquis hit one Sept. 22, 2008, in New York against the Mets, and first by a Cubs pitcher at Wrigley Field since Burt Hooton hit one Sept. 16, 1972, against the New York Mets.

Wood was good on the mound, too, allowing two runs in six innings.

Peavy (6-3) allowed six earned runs and eight hits in four innings. He also gave up four straight hits in the second inning for two runs that put the Cubs ahead for good.

It was Peavy's worst start since giving up six runs April 9 at Washington in 5 1-3 innings.

"I felt good," Peavy said, discounting the idea he might have pitched too many innings in recent starts. "There was no excuse of it whatsoever."

With two outs in the second, Valbuena doubled, Barney singled him home, Wood singled and David DeJesus singled in Barney for a 2-0 Cubs lead.

"I've got to make better pitches there in the second," Peavy said.

Schierholtz homered leading off the fifth against reliever Nate Jones for a 7-1 lead and Valbuena hit a leadoff homer off Brian Omogrosso in the eighth.

"I think man for man everybody in here will tell you we got outplayed," Peavy said. "We didn't play with the intensity we need to play with. We didn't make plays. We didn't make pitches. We didn't get hits."

NOTES: The Cubs called up right-hander Zach Putnam from Triple-A Iowa and sent down right-hander Alex Burnett, a former Baltimore pitcher whom they signed off waivers Monday. Putnam had one inning of scoreless relief. ... A day after hitting three home runs in one game, Cubs catcher Dioner Navarro was back on the bench with Castillo in the lineup. ... The Cubs came into the game with the third-most errors in the NL (39) and the White Sox with the most in the AL (35), and both teams committed errors in the first inning