But the Chicago left-hander tinkered with the grip on his sinker and became even more dominant than usual against the Royals, taking a four-hit shutout into the ninth before settling for a 4-1 victory that gave the surging White Sox their sixth win in a row.
"I had everything working," said Buehrle (8-2), who raised his career mark against Kansas City to 20-8. "I changed my sinker grip in the bullpen because the last two or three games, it's been cutting instead of sinking. So I moved my fingers closer together and I think it was probably one of the best sinkers I've had in a while."
Buehrle failed to get his first complete game since May 2, 2008, when Alberto Callaspo doubled and scored on David DeJesus' one-out double. He was relieved by Bobby Jenks, who got the last two outs for his 19th save in 21 chances for the White Sox, who have won 10 of 12 and 14 of their last 19 on the road.
Until the ninth, the 30-year-old Buehrle had been dominant. He did not issue a walk and had a season-low one strikeout in 8 1/3 innings. He threw 68 strikes in 100 pitches.
"That's kind of embarrassing to get only one strikeout," he said. "But it's good to put the ball in play early and go deep in games. I'll take this every time, obviously."
Mark Teahen, one of the few Royals hitters who seems to have much luck against the 30-year-old Buehrle, was 2 for 3, raising his career mark against him to .440.
"I asked him if he'd sign [the ball]," said Buehrle with a grin. "I finally got him out."
Teahen grounded out in the eighth.
"He's tough. He really is," Teahen said. "He mixes up all his speeds, pitches both sides of the plate. You want to be selective with the guy. But when he's pounding the strike zone, throwing all his pitches for strikes, it's hard to be too patient."
Chen went six-plus innings plus two batters and gave up two runs on five hits. Making his second major league start since undergoing Tommy John surgery in late 2007, Chen walked one and struck out five and did not allow a hit until Nix sent a 2-2 pitch sailing into the visitors bullpen leading off the fourth.
The left-hander, looking for his first victory since Oct. 2, 2005, was not threatened again until Jim Thome doubled under David DeJesus' glove leading off the seventh and Paul Konerko followed with a shallow single.
"I felt pretty good," Chen said. "I felt I mixed my pitches and I was keeping the ball down. I felt like I gave my team a chance to win."
Reliever Ron Mahay came in and got a double-play grounder from A.J. Pierzynski that allowed Thome to make it 2-0. Scott Podsednik's RBI single off Mahay made it 3-0 in the eighth. Gordon Beckham drove in the fourth run in the ninth.
The Royals helped Buehrle by running themselves into two embarrassing double plays. Willie Bloomquist singled with one out in the first but was doubled off first after Billy Butler flied out to center field. Then Teahen singled with one out in the second and failed to get back to the bag in time when Miguel Olivo flied out to right fielder Jermaine Dye.
"It just seems like everything's working for us," Buehrle said. "A ball in the dirt, guys are getting to second base on it. Then a base hit right after that. When you're playing good, it seems like everything's working for you."
Royals manager Trey Hillman had a different perspective on the baserunning blunders.
"It didn't help at all. You've got to check and pick up the ball when you're in motion like that," he said. "Willie checked but couldn't pick it up. Mark didn't check and went too far and couldn't get back."
X-rays on Alexei Ramirez's right middle finger were negative but manager Ozzie Guillen was not sure how soon the White Sox shortstop would return to the lineup. Ramirez was hurt Wednesday in the game at Cleveland. ... The Royals went over the 1 million attendance mark, seven dates earlier than in 2008.