Kevin Gregg faced six batters in the ninth inning and didn't record an out. An 8-1 lead was down to 8-4 as he walked off the mound to a chorus of boos.
Three straight singles, two straight walks and another single accounted for three runs.
Jim Johnson replaced Gregg and struck out Andy Dirks on three pitches. The fourth run of the inning scored on Magglio Ordonez's bouncer to short. Miguel Cabrera was walked intentionally to load the bases - a risky move, considering the go-ahead run came to the plate - but Nolan Reimold ran down pinch-hitter Brennan Boesch's liner toward the left field line.
Johnson is credited with his second save.
Gregg hadn't allowed a run or hit in his last five outings.