The best team in the American League since the All-Star break appears poised to wind up as the best team in the AL Central at the end of September.

The White Sox extended their winning streak to six games Saturday night with a 13-2 thrashing of the Texas Rangers in front of 33,721 fans at U.S. Cellular Field. The Sox retained a one-game lead over Kansas City and extended their lead over third-place Minnesota to 2½ games.

Frank Thomas slugged a pair of home runs and drove in five runs. Mark Buehrle improved to 11-12 with his 50th career victory, and the Sox, who rapped out 17 hits, are 24-12 in the second half of the season.

"I know it's a long haul, there's no doubt about it," said Sox manager Jerry Manuel. "Even coming out of spring training you have to be careful. I mean, everybody likes to get off to a good start and play everybody and get all the pieces in the right places. But it's 162 games and you have to prepare your team for that."

Thomas hit his 33rd homer of the season in third inning off Rangers starter Ismael Valdes. The three-run shot gave the Sox a 3-0 lead.

In eight career at-bats against Valdes, Thomas has five hits, including four homers and eight RBIs.

"I believe if I had thrown the ball in the dirt they would have hit it," said Valdes (7-8), who was charged with six runs on nine hits in 32/3 innings.

After Jay Powell took over for Valdes, Thomas punctuated a six-run fourth inning with his 34th homer.

Thomas attributed his hitting to "relaxing and getting good pitches to hit."

"I'm just having good results right now," he said. "I hit the second home run better than the first one. The first one, I thought, was just going to be a double. But it carried out, barely."

Buehrle, a 19-game winner last year, went 0-9 in 12 starts from April 15 through June 11 before rebounding with a 7-0 stretch over his next nine outings. He's 9-2 over his last 14 starts.

"Buehrle's record in the first half was a mirage," said Sox pitching coach Don Cooper. "He was a lot better than 2-10. He was an atypical Buehrle. But now he's stereotypical Buehrle."

Buehrle is 4-0 in seven career appearances, including three starts, against the Rangers. He went six innings Saturday, allowing one unearned run. He walked one and struck out three.

"As soon as I came out there I told the guys to score a lot of runs because I didn't feel like I had anything. My arm felt kind of tight," Buehrle said. "I told them to score me 10 runs. They kind of laughed at me, but once I got out there on the mound I kind of settled down and hit my spots. Everything was working for me."

Cooper said he believed Buehrle was due for some good fortune in the second half of the season.

"He was maybe not as sharp as he had been in the past, but if you look back at some of his games, a lot of crazy stuff happened," Cooper said. "Missing pop flies in Oakland, a fog ball [missed] here against Oakland. He had some bad luck."

Besides Thomas, Jose Valentin and Joe Crede hit back-to-back homers in the fourth inning. Carlos Lee also homered in the seventh inning, matching his career high with 26 on the season.

Crede also matched a career high by going 3-for-4.

The Sox have posted their longest winning streak since winning seven straight from Aug. 27 to Sept. 3, 2002.