The Athletics ended a two-game skid with an offensive show featuring a 4-for-4 performance from Reddick.
He scored Oakland's opening run in the first inning, hit a solo homer in the third, had an RBI single in the sixth and then smashed a three-run blast in the seventh. He has eight home runs for the season, more than he has had in any of his previous three major league campaigns.
Tommy Milone (5-2) was the beneficiary of the Oakland outbreak, picking up the victory by allowing two runs on five hits over seven innings. He struck out six.
Detroit starter Rick Purcell (3-3) lasted five innings. He surrendered four runs on nine hits and left with the Tigers facing only a two-run deficit.
Three Detroit relievers combined to give up seven runs on just four hits.