DETROIT -- The defining moment of the Tigers' opening half of the 2014 season might not have come until its final series.

Rajai Davis, the catalyst, didn't mince words when asked to describe Detroit's outlook Monday facing a three-run deficit in the bottom of the ninth inning of its series opener against the team with the best record in baseball.

"Your game is over," Davis said Wednesday, after the Tigers completed a sweep of Oakland with a 9-3 win spurred by a six-run sixth inning. "For most teams, that game is over. Especially at this level. Especially against a closer that's pitched exceptionally well."

By now, you know how that story ended. With one swing of the bat against A's closer Sean Doolittle, Davis cleared the left-field fence and the bases.

"Until Rajai's grand slam, we were a little flat offensively," Tigers manager Brad Ausmus said. "From the grand slam on, I thought we had good at-bats."

After the game Wednesday, Davis said he "absolutely" sensed that the series turned on a dime with the improbable comeback Monday night.

The emotional roller coaster that the Tigers took themselves and the fans on Monday night was a microcosm of the entire first half, which Detroit completed Wednesday with a 47-34 record. The Tigers sit 4 1/2 games above the Royals for first place in the American League Central, a position they briefly relinquished for a few days last month but have otherwise kept a stranglehold on.

Game No. 81 was a statement game like none before it. While players have been loath to call it a rivalry, Detroit and Oakland have met in the postseason each of the past two years. If the Tigers are going to capture their second pennant in three years, the A's have seemed like the biggest roadblock since April.

And in another microcosm of the first half, Detroit won even though Justin Verlander wasn't at his best. Verlander allowed two first-inning home runs, though he eventually settled in and lasted six solid innings to earn his first win since May 30.

The Tigers also managed to sweep the A's without Victor Martinez, who has been resting a sore side since Monday.

The damage instead came from the outfield, including usual right fielder Torii Hunter -- who was slotted as designated hitter for the first time in his Detroit career. Hunter combined with Monday's hero Davis, Austin Jackson and J.D. Martinez to go 9-for-17 with six RBIs.

Jackson was in the leadoff spot for the third time in the past four games. That's where he has batted for the vast majority of his big league career, but Ausmus had previously used him there only once since taking over last offseason.

The switch to leading off comes as an attempt to re-harness Jackson as a productive bat in the Tigers order.

"He looked good. He looked really good," Ausmus said of Jackson. "Even in his last at-bat, he hit that ball hard at the first baseman. He'll be back there again tomorrow.

"Whoever's leading off -- and it will be Jackson again tomorrow with J.D. in the lineup and Torii in the lineup, you stretch the lineup out quite a bit."

Suddenly, with the offense picking up Verlander on a day when he was good, not great, the 9-20 stretch that temporarily dethroned the Tigers felt ages away.

Ian Kinsler, the veteran prize added to the Detroit roster this offseason, feels that weathering that storm has paid off.

"We've handled it really well," Kinsler said of a first half that was up, then down, then up again. "I think it was good for our team to go through some of those tough patches. It taught us a lot about what type of team we are, that we can come out of that sort of thing and be one of the better teams in baseball.

"It's healthy. When you can use it as a positive and continue to win games, hopefully it makes your team stronger."

Ausmus waxed poetic about the quality of characters in the Detroit clubhouse when asked what he enjoyed most about his first half-season as a big league manager.

As for what Ausmus has liked the least from his first-place team?

"There's nothing I dislike about the team."