CHICAGO -- Manager Ozzie Guillen admitted that playing .500 baseball probably isn't going to be enough to win the American League Central.

But for now, the White Sox skipper and his players couldn't feel any better about being so middle-of-the-road.

Following a 6-2, come-from-behind victory over the A's on Monday night at U.S. Cellular Field, that's exactly where the White Sox stand -- a pedestrian 25-25.

It only seems as though the White Sox are in a better position thanks to a searing 10-3 stretch in their last 13 games.

"Somebody said the other day we were one game behind .500, and I was like, 'Really?'" White Sox starting pitcher Gavin Floyd said. "I thought we would be ahead. But we've been playing really well, and we're just going to keep grinding."

Floyd was among those who grinded it out on Monday. He did not receive credit for a decision in seven innings, but he kept the White Sox in the game long enough for another hero to emerge.

That hero was 19-year veteran Jim Thome, who mashed a tie-breaking, three-run home run in the bottom of the eighth inning to push the White Sox ahead, 5-2.

The 389-foot homer to left-center field off A's reliever Santiago Casilla gave Thome nine on the season, 550 for his career and propelled the White Sox to their fourth straight victory.

Even at 38 years old, playing the role of hero never gets old for Thome.

"No, not in a 'W,' not in a win," Thome said. "You like to contribute. You like to put the time and work in. When you see success, it means a lot."

A's manager Bob Geren said Casilla was trying to bounce a curve to Thome but left it right out over the plate.

"You do that with any hitter, it's probably going to get hit hard," Geren said. "Do it with a guy like Thome, it's probably going to go a long way -- and it did."

The A's took a 2-0 lead against Floyd four batters into the game when Matt Holliday parked a two-run home run 418 feet into the left-field seats. Jack Cust, who singled one batter earlier, scored on the homer.

"He didn't get all of it," Floyd joked about Holliday's blast. "No, he crushed it. But you give up a home run, you give up a home run. You just ignore it and try to keep your team in the game."

Floyd followed that mantra completely on Monday.

Over the next six innings, he was marvelous, including a stretch of retiring 11 straight batters between the fourth and seventh.

Not until the seventh did Floyd encounter any semblance of trouble. With two outs in the inning, Floyd allowed Oakland's Nos. 7-8-9 hitters all to reach base. He walked Ryan Sweeney, surrendered a single to Aaron Cunningham and another walk to Jack Hannahan.

That set the scene for a bases-loaded matchup against shortstop Orlando Cabrera, who played a key role as part of the 2008 American League Central champion White Sox last season.

Already having thrown more than 100 pitches, Floyd buckled down for one last batter. He got ahead of Cabrera at 1-2, and then fooled him with an 86-mph slider to escape the jam.

Floyd finished the night with 107 pitches.

"Every day this kid learns how to pitch," Guillen said. "Today, he got himself in trouble and he gets himself out of trouble. That's a good sign about good pitching about a good future. Some people with not that many years in the big leagues, they panic and start walking people. They try making the wrong pitches. He threw a couple pitches to Cabrera that were outstanding pitches. ... I think he's learning little by little, and this kid's learning how to pitch."

Floyd, whose ERA stood at a season-high 7.71 on May 17 after an 8-2 loss to the Blue Jays, produced his third straight quality start and lowered his ERA to 5.75. He allowed two runs on four hits while striking out eight in his third consecutive start.

"He's started throwing strikes," catcher A.J. Pierzynski said of Floyd's last three outings. "That's the biggest thing. When he's ahead in the count, he has stuff to put guys away. He's getting ahead of guys and using all of his pitches."

The White Sox kept the game tight with a run in the first and fifth innings. Leadoff hitter Scott Podsednik scored from third on Jermaine Dye's sacrifice fly to right field in the first. And in the fifth inning, Pierzynski tied the game at 2 with a solo home run to right.

Following Thome's homer, the White Sox tacked on another run when Jayson Nix coaxed a bases-loaded walk that scored Paul Konerko.

Chicago reliever Matt Thornton (3-1) pitched a scoreless eighth to earn the victory, and Scott Linebrink closed out the A's in the ninth.

With the win, the White Sox returned to the .500 mark for the first time since being 12-12 on May 3.

They have captured the first game in each of their last five series and have climbed into second place during this run, moving within 3 1/2 games of the first-place Tigers.

Yes, .500 never felt so good.

"It's exciting to be .500 because we were so far away," Guillen said. "Now, hopefully the ball continues to roll our way and hopefully we continue to win games."