DETROIT — It was shaping up to be a really, really bad day at the end of a really bad week for the Detroit Tigers.

They were one out away from being swept in a four-game series at home for the first time in nine years. They had already seen their offensive leader, Miguel Cabrera, hobble off the field, and their Cy Young candidate get knocked out early.

That was before Torii Hunter lofted his two-out, three-run, walk-off home run into the bullpens in left field.

The come-from-behind win — at five runs, their biggest deficit erased this season — left the Tigers (78-56) six games up in the American League Central race.

Which was right where they’d started four days earlier.

When Atlanta finished off a three-game sweep of the second-place Indians (71-62), it pushed Detroit’s cushion to 6 1/2 games.

Meaning the Tigers had come within one out of a demoralizing sweep at the hands of the team they’d beaten in five games in last year’s AL Division Series, and actually GAINED GROUND.

Now, the Indians head to Comerica Park for a three-game set.

“We’ve got Cleveland coming tomorrow. We were fortunate we didn’t get swept ’cause they (the A’s) beat us up good, to their credit. I tip my cap to them, they’re a good team. They came in and they were very hot, very aggressive. I tip my cap to ’em but we got the one game and it was an important game but now we’ve got to zero in on Cleveland coming tomorrow,” Tigers manager Jim Leyland said after the game.

“The guys are good, their spirits are good, they’re playing hard. People forget we just won three in a row. We lose three in a row, they think it’s the end of the world. We just won three in a row in New York. It’s hard to win up here. This is a real good team. They are the Western Division champion.

“We did go five games with them in the playoffs. It’s just not that easy.

“They beat us up pretty good. But we hung in there, and we finally got one.”

Worst-case scenario, the Tigers could head into September with just a 3 1/2 game lead, should the Indians put together a sweep.

Best-case, the Tigers could head into the final month with a nearly-insurmountable 9 1/2 game lead, if they sweep the Indians, head-to-head, like they did in the last meeting between the two teams.

Hunter, the author of the walk-off win Thursday, believes there’s some momentum to be taken from that victory.

“I think that kind of gives you a boost, when you get somebody to hit a walk-off home run or walk-off base hit, it carries over,” he said.

“In this series against the Indians, it’s gonna be intense. It’s gonna be intense on both sides. We’re trying to separate from those guys and they’re trying to catch up. So look for some good professional ball this weekend. Don’t miss it. Don’t miss it. It’s gonna be beautiful this weekend. We want a sellout, we want to be loud. I don’t want to hear nobody quiet. I want to hear loud crowds, all right? You hear me?”