The Mariners lead the race by the slimmest of margins, .001 to be exact. The Tigers remained one game behind both the Mariners and the Yankees after losing to the A's on Friday.
In the end, though, the White Sox capitalized on their opportunities when it mattered most, while the Mariners squandered away multiple late-inning chances.
Knotted at three in the seventh, Seattle loaded the bases with just one out, but Fields gunned out Kenji Johjima at the plate after bobbling a possible double-play ball before Jose Guillen grounded out to second to end the threat.
Chicago promptly scored two runs in the bottom half of the inning, which would be all it needed to pick up the win.
"I didn't sense any momentum switch," Washburn said. "It's tough when you have a scoring opportunity and you don't capitalize, but Vazquez did a great job pitching right there, and it's my job to go in and put up a zero, and I didn't do that, and it cost us the game."
Washburn lasted 6 2/3 innings, allowing five runs on seven hits while striking out six. He threw 120 pitches, but said he felt fresh throughout the game.
"I was ready to come out [for the seventh]," Washburn said. "I still felt I had good stuff. The whole game, I felt like I'd thrown better than I had in quite a while."
He is 0-3 with a 6.00 ERA throughout his last six starts, and suffered his first loss against the White Sox since he was with the Angels in 2005.
Washburn held Chicago in check through most of the game, but made just enough mistakes in the seventh for the White Sox to capitalize on. Juan Uribe hit a go-ahead RBI double and later scored on a bloop triple that just rolled past a sliding Ichiro Suzuki.
"I made a few mistakes," Washburn said about his seventh inning. "The one to Uribe was a mistake. ... Up to that point I hadn't made too many mistakes, but they made me pay when I did."
Ichiro, meanwhile, did everything he could defensively to help keep the Mariners in the game.
Ichiro climbed so high up the wall on Fields' home run in the sixth he nearly sat down on top of it, but was unable to stretch high enough to catch the home run. Even though he didn't make the play, he wouldn't rule out giving the same -- or greater -- effort on future plays, depending on the circumstances.
"I never have in the past, but the next step would be to climb the wall, and then jump. That would be the maximum," Ichiro said through translator Ken Barron. " On that particular ball, I wouldn't be able to do it, but there's a possibility I'd do it in the future; Maybe for a big game, a situation where it's worth taking the risk."
His skipper certainly appreciated the effort from the six-time Gold Glove winner.
"[Ichiro] gave a great effort on the bloop, too," manager John McLaren said of Uribe's RBI triple. "You can't defend bloops, it's just one of those things."
The Mariners threatened again in the eighth inning when Raul Ibanez and Adrian Beltre both reached base safely to open the inning.
Richie Sexson hit into a double play, though, and Johjima grounded out to end the threat. Reliever John Parrish, acquired from the Orioles on Thursday, made his debut with the Mariners in the eighth, where he retired all three batters he faced.
"I was shaky a little bit, but I kept it together and got the outs," Parrish said. "When I get out there, it's always just, turn it off, and focus on getting them one at a time."
Ibanez finished the game 3-for-4 with a home run, his fourth in as many games. Designated hitter Jose Vidro had his 11-game hitting streak snapped.
"We just missed some opportunities, and Fields hit a couple home runs," McLaren said.
Washburn was made painfully aware of that by the time Friday's game had concluded.
"That was the first time I ever faced him," Washburn said. "He's got some power."