OAKLAND, Calif. -- Same chaotic, champagne dance-party scene in the clubhouse just two days later. New T-shirt: AL West champions.

The Oakland Athletics won the division title with another improbable rally in a season full of them, coming back from four runs down and a 13-game division deficit to stun the two-time defending league champion Texas Rangers 12-5 on Wednesday.

"We knew this is a beast of a team we would have to beat, and to be able to beat them three games in a row and win the division on top of it, really it's a magical-type thing," manager Bob Melvin said.

Josh Hamilton dropped a fly ball in center field for a two-run error that put the A's (94-68) ahead 7-5 in a six-run fourth inning. The A's only added to Texas' troubles the rest of the way.

While Hamilton's Rangers (93-69) are headed to the new one-game, wild-card playoff, the A's get some time off before opening the division series in their first postseason appearance since 2006.

"You can have all the experience as you want but when you run into a team that's hot, experience has nothing to do with it," Texas manager Ron Washington said.

The A's will open the division series Saturday at the Detroit Tigers. Texas hosts the Baltimore Orioles in a wild-card game Friday, with the winner of that contest then facing the New York Yankees.

The A's needed a sweep and they delivered to win their first division crown in six years and 15th in all. They overcame a five-game deficit in the final nine days and took sole possession of the West's top spot for the first time this year.

"It shows how important Game 162 is," Oakland's Jonny Gomes said. "I don't think it took 162 to games to check the character of this ballclub."

Grant Balfour retired Michael Young on a fly to center for the final out, then raised his arms in the air as the A's streamed out of the dugout and began bouncing up and down in the infield.

"2012 AL WEST CHAMPIONS" flashed on the scoreboard two days after the A's clinched a playoff spot Monday and held a wild dance party in the clubhouse.

"I'm glad there's not one tomorrow or Friday," owner Lew Wolff said. "I can relax and go home. I'm running out of underwear."