OAKLAND, Calif. — The Oakland Athletics had been down and doubted so many times during this remarkable year that a four-run deficit against the two-time reigning AL champions hardly fazed this get-after-it bunch.

They rallied, thanks to the same grit and determined, prove-you-wrong approach this group has demonstrated since Day 1.

From 13 games back on June 30 to AL West champions on the final day.

“We knew all along we had the chance to do it,” right fielder Josh Reddick said. “We swept New York here, we swept Boston here. Doing it to these guys was never out of the question.”

The A’s captured their first division crown in six years with another improbable rally in a season full of them, coming back once more to stun the Texas Rangers 12-5 Wednesday.

The A’s needed a sweep and they delivered. 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.

“I don’t think a single one of us was worried,” said Brandon Moss, who drove in three runs. “We weren’t supposed to be here, for one. For two, they were the ones with everything to lose today.”

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.

The A’s are Motown-bound again.

While Hamilton’s Rangers (93-69) are headed to the new one-game, wild-card playoff at home against Baltimore on Friday, the A’s get two days off before opening the division series at Detroit on Saturday in their first postseason appearance since being swept by the Tigers in the 2006 AL championship series.

It was snowing in Detroit when the A’s arrived in the Motor City that time.

“It’s going to be a tough matchup,” manager Bob Melvin said. “They have a very powerful lineup that can certainly score some runs. They also have great starting pitching. “