DETROIT -- The Oakland Athletics avoided a three-game sweep, yet still came out on the losing end.
Seth Smith homered, doubled and drove in four runs, and the Athletics beat the Detroit Tigers 12-4 in a matchup of AL playoff contenders. But the wild-card co-leaders also learned they would be minus starter Brett Anderson for the remainder of the regular season.
An MRI revealed Anderson sustained a Grade 2 strain of his right oblique muscle on Wednesday night, when the left-hander awkwardly fell off the mound and exited after two-plus innings.
Anderson was 4-2 with a 2.57 ERA after six games while coming off Tommy John surgery. The A's revealed the extent of his latest injury after their victory.
"He's a guy that's got ace-type of stuff. It hurts to lose a starting pitcher," Athletics manager Bob Melvin said. "But we've lost a lot of starters in the last month and a half, three."
Melvin said he doesn't know about Anderson's availability for the postseason.
The team also is without Brandon McCarthy, who was hit in the head by a line drive, and Bartolo Colon, who was suspended for using a performance-enhancing drug.
Both clubs are in second place in their divisions, and Oakland is even with Baltimore for the wild-card spot.
The Tigers are two games behind the Central-leading Chicago White Sox.
Outscored 18-4 in the first two games, Oakland held down Miguel Cabrera to win the finale. Cabrera singled in four at-bats, and tops the AL in batting at .333.
Josh Donaldson hit a go-ahead single in a four-run sixth inning that made it 6-3, then had an RBI double to cap a six-run ninth that included Smith's three-run double.
"We're not the type of team to score a run here, a run there, two runs here. We're more of a big-inning team, more often than not," Smith said.
Pat Neshek (2-1) retired the only batter he faced and got the win.
Anibal Sanchez (3-6), who held Cleveland hitless for 6 2-3 innings in his last start, gave up six runs on six hits and two walks in 5 2-3 innings.
Smith hit his 14th homer, a solo shot in the fifth that made it 2-all. The Tigers retook the lead in the bottom half when Cabrera singled and scored on Prince Fielder's double.
The A's went ahead for good in the sixth. Brandon Moss hit a tying double with one out and after Chris Carter struck out and Smith was walked intentionally, Donaldson singled.
Phil Coke relieved and George Kottaras hit a liner that center fielder Austin Jackson misjudged, the ball sailing over his head for a two-run triple.
"It kind of knuckled. I was right there. It just took a left turn on me," Jackson said.
Kottaras felt fortunate.
"I knew I hit it good. I saw him coming in. I thought, `Oh no, he's going to catch it,'" Kottaras said. "Then when I saw it go over his glove. I was like `Great!' But then I thought, `I've got to keep running.'"
Andy Dirks led off the Detroit sixth with a home run off Jerry Blevins.
Yoenis Cespedes hit a bases-loaded sacrifice fly to start Oakland's scoring in the ninth.
The Tigers threatened in the first against Tommy Milone, loading the bases before Delmon Young grounded into an inning-ending double play.
"We missed a couple opportunities," Tigers manager Jim Leyland said. "Delmon hit a ball right on the button in the first inning, double-play ball, he hit it right on the nose. We had a couple other opportunities. We had some chances."
Detroit broke through in the second to take a 2-0 lead on Gerald Laird's RBI single and Jackson's sacrifice fly.
Second baseman Omar Infante's throwing error on an attempted double play gave the A's a run in the third. It was his 10th error in 51 games since being acquired from Miami, along with Sanchez, on July 24.
NOTE: Detroit C Alex Avila is no longer having headaches, according to Leyland. Avila sprained his jaw when he collided with Fielder chasing a foul ball on Sunday. ... Cespedes was the designated hitter because of a bone bruise on the bottom of the outfielder's foot that has lingered for the last few days. ... Oakland OF Coco Crisp missed his second game because of an eye allergy. ... The Athletics travel to New York for a three-game weekend series. Jarrod Parker faces CC Sabathia on Friday night. ... Rick Porcello and the Tigers host Sam Dedundo and Minnesota on Friday night.