CHICAGO -- Josh Donaldson checked out the video and figured out the problem. The quick fix led to a big night.
Donaldson also scored two runs as Oakland got just its third win in 12 games.
It was quite a turnaround for Donaldson after he struck out four times the previous night. Watching video at the hotel after Monday's game, the All-Star third baseman noticed the position of his hands was throwing off his timing.
"I think baseball is just a stupid game," he said. "It's just one of those things where last night, I didn't even come close to touching anything -- four punches. Tonight, I was able to get the most hits in my career in one game. You just try to turn the page, try to forget it."
Lester (14-10) gave up two runs over eight innings, and the Athletics took advantage of a season-high five errors by Chicago.
The Athletics are trying to hang on to a wild card after plummeting out of the AL West race, and they came away with a much-needed win.
Lester gave up seven hits, struck out eight and walked two after going 0-3 in his previous four starts.
He was sailing along with a 5-0 lead when Dayan Viciedo homered leading off the seventh. Carlos Sanchez got thrown out trying to stretch an RBI double to a triple, ending the inning, and Oakland pulled away.
Chicago's John Danks (9-11) lasted six innings, allowing four runs -- two earned -- and seven hits. He is 0-5 in his past eight starts.
Third baseman Marcus Semien had a rough night with three errors, and the White Sox lost for the fifth time in six games.
"I can look at the plays all I want," Semien said. "I can practice them. I just want to come back tomorrow, have a good day of work, and if I'm in there, forget about today and move on."
Donaldson singled and scored in a two-run fourth, and then added a two-run double in the fifth to make it 4-0. That hit came right after Gentry left the game.
Coco Crisp had just reached on an error leading off the inning when Gentry got down a bunt toward the right side. He beat Danks' throw, but his head collided with Sanchez's shoulder while the second baseman was covering the bag.
Gentry stayed down for several minutes, holding his head while being tended to, before walking gingerly off the field.
"That's tough to see," Lester said. "That's kind of the whole personality behind this team. You go hard until you get knocked down. We try to use it as a figure of speech, not actually literally go out there and get knocked out. Hopefully it's not that bad."
Athletics: Closer Sean Doolittle (strained muscle in the rib area) will throw a side session Wednesday and, barring a setback, could rejoin the bullpen Thursday, manager Bob Melvin said. ... Melvin hopes C John Jaso will be cleared to play after he consults with concussion expert Dr. Micky Collins in Pittsburgh on Wednesday. ... Melvin said C/OF Stephen Vogt (sprained left ankle) is improving but is not ready to resume baseball activities.
White Sox: Manager Robin Ventura isn't sure when retiring 1B Paul Konerko (fractured left hand) will be ready to swing again. He is expected to return before the season -- and his career -- ends.
Tuesday's game aside, it's no secret Oakland has struggled on offense since sending Yoenis Cespedes to Boston in the Lester trade. But when asked whether the Athletics are missing the slugger, Melvin sidestepped the question.
"The balance was, do we have enough offense or do we need more pitching?" Melvin said. "And that's what we came to terms with, is when you get a Jon Lester, you get a Jon Lester, and we try to mix and match and pick up the pieces where Ces was."