Deduno (3-1) won for third time in four starts, yielding seven hits and a walk while striking out two. The right-hander tossed 64-of-93 for strikes and benefited from two Minnesota double plays.
Plouffe (3-for-3) bashed a two-run homer in the fourth inning to erase a 2-0 deficit and supplied an RBI hit in the seventh for a 6-2 Twins lead.
In between, Joe Mauer delivered a two-run single and Brian Dozier also drove in a run against Darin Downs (0-2) as Minnesota evened its three-game series against the American League Central leaders.
Tigers starter Anibal Sanchez lasted only 3 2/3 innings, surrendering four walks and five hits Minnesota parlayed into runs.
Jhonny Peralta supplied two RBI for Detroit.