After paying Peavy a visit, Chicago manager Robin Ventura liked what he heard -- and what he saw after their talk.
Mauer popped out to end the eighth with speedsters Denard Span on third and Ben Revere on first. Ventura said he wasn't sure if he'd leave Peavy in when he walked from the dugout to the mound. He wanted to make sure Peavy was still comfortable facing Mauer, the three-time American League batting champion, in that situation.
"He still wanted it. I trust him," the first-year manager said.
Peavy (9-7) allowed five hits and walked two. He said he was confident against Mauer, based on the way he'd pitched to him previously.
"Just decided to stay hard in and try to get a ball in the air," Peavy said.
One of the runs Peavy gave up was unearned, due to a way-wide token pickoff throw to second base in the first inning that sailed into center field. The miscue let Revere move to third, and he scored on Mauer's groundout.
Danny Valencia homered in the second, but Peavy toughened up after that to lower his ERA to 3.04 and notch just his third victory since May.
Addison Reed pitched a shaky-but-scoreless ninth for his 18th save in 21 attempts and the White Sox improved to 9-1 in their last 10 one-run games. They have won seven of nine overall.
"Just wanted to make it more interesting," Reed said, smiling.
Brian Dozier flied out to end the game with runners on second and third.
"That's part of being a closer. I don't think it can always be clean," Ventura said. "He's used to it. It doesn't seem to affect him, even in big games when it doesn't seem to go so well."
Diamond (9-5) had one out in the eighth inning with Tyler Flowers on third when De Aza hit a sharp liner that glanced off Diamond's thigh. The left-hander was a bit stunned, and his short throw home was well off target as Flowers scored the go-ahead run.
De Aza created his own run after leading off the game with a single, moving up on a stolen base, a groundout and Adam Dunn's sacrifice fly. Flowers almost hit into an inning-ending double play in the fifth after a diving stop by Dozier, but the shortstop had trouble getting the ball out of his glove and Flowers beat the relay throw to first as Alex Rios scored the tying run.
The AL Central-leading White Sox began the first day of the month 2 1/2 games ahead of Detroit. This is the fifth time since 2000 that they have started August in first place, and including their 2005 World Series title they made the playoffs in three of the previous four.
"One thing with the Whities: They have a good pitching staff, and you're going to face some tough pitchers. Doesn't matter which one they throw out there, including Liriano. It's going to be a battle scoring runs," Twins manager Ron Gardenhire said.
Bothered by an elbow injury in 2008, an ankle problem in 2009 and shoulder trouble in 2010 and 2011, Peavy is back on track. This was his 21st start of 2012, his most since 27 turns in 2008 for San Diego. The 2007 National League Cy Young Award winner made a total of only 51 starts in the majors over the three seasons prior to this one.
"Not yet. I feel excited to be able to help up to this point. But we want to win," Peavy said: "It certainly does feel gratifying to be able to be healthy for the team, like I've wanted to be the whole time that I've been here."
The White Sox are off Thursday before beginning a nine-game homestand by hosting the Los Angeles Angels on Friday. RHP Phil Humber (5-5, 5.90 ERA) pitches for the White Sox against Zack Greinke, who will make his second start for the Angels. ... Liriano will make his second start for the White Sox on Sunday, followed by Peavy on Monday. Sale will pitch Tuesday with 10 days of rest, and Quintana will throw Wednesday after an eight-day break while the White Sox use a six-man rotation to protect their young pitchers from overuse. ... The Twins start a four-game series in Boston on Thursday. RHP Samuel Deduno (2-0, 3.13 ERA), coming off his strongest of four starts this season, faces LHP Jon Lester (5-8, 5.49). ... The White Sox have drawn only two walks and committed seven errors in their last four games.