Zito (12-10) gave up four hits and three walks and struck out six.
"I was kind of lethargic mentally," he said. "But that works to my advantage. It helps me not freak out because you're not attentive to every little hit, or what a fan is saying. It's better just to be in a little bit of a daze."
In the first, Zito got out of a bases-loaded, one-out jam with a double play.
"That was probably the crossroads of the whole game," Oakland manager Ken Macha said.
After benefiting from the double play, Zito didn't allow a runner to reach second until the sixth inning. He started in Rich Harden's place, and somebody else will have to take Harden's scheduled start on Saturday because of his shoulder injury.
Oakland won its second straight -- after dropping seven of nine -- to remain in a tie with the Yankees for the AL wild-card lead.
Are the A's -- who were 39-14 in June and July -- back on a roll?
"I'll be curious to see myself because on Tuesday, that wasn't the same club," Tigers manager Alan Trammell said. "They got it together the last couple of days. They're playing very well, but for whatever reason, when [Eric] Chavez came back yesterday it
seemed to give them a little lift."
Chavez was back in the lineup Wednesday after missing a game to be with his wife, who gave birth to the couple's first child.
Until a 9-2 victory Wednesday, the A's had not scored more than five runs in 13 straight games, dating to an 11-0 win Aug. 7 at Kansas City.
"If I could figure out this team, I'd be a genius," Ellis said. "We're all either swinging the bat well at the same time, or not."
Zito suffered from Oakland's recent lack of run production. He was 0-2 in his previous three starts, despite a 3.26 ERA during that stretch.
He was able to pitch with an early cushion Thursday.
Oakland scored two in the first, one in the second, two in the third, three in the fourth and one in the fifth to build a huge lead Zito didn't even need because he was pitching so well after his shaky start.
Detroit's Mike Maroth (11-12), who had won three straight decisions, had his worst outing of the year, lasting just 3 2/3 innings. He gave up a season-high eight runs -- matching a career high -- and 10 hits.
"I was leaving a lot of balls over the plate," Maroth said. "I pretty much did what you don't want to do as a pitcher. It seemed like I was getting behind hitters, and when I did get ahead, I wasn't able to put them away."
Kendall started Oakland's barrage with a leadoff single in the first and scored on Chavez's single, and Kielty's RBI single made it 2-0. Ellis hit a solo homer in the second.
Kielty drove in another run with a groundout before Johnson made it 5-0 in the third with an RBI single.
Tigers right-hander Jeremy Bonderman, whose right wrist was struck by a line drive Wednesday, said he plans to play catch on Friday and hopes to not miss his next turn in the rotation. ... In a best-case scenario, Harden would return to the rotation Thursday against the Angels. ... The 2005 All-Star Game and related activities in Detroit generated more than $52 million in spending in southeastern Michigan, according to an analysis released Thursday.