Deduno, who went 6-5 in 15 starts for the Twins last year, was called up from Class AAA Rochester last week and gave up six runs to Detroit in his season debut.
Against the Brewers, however, Deduno (1-1) allowed the lone run with two strikeouts while throwing 100 pitches. Casey Fien needed just seven pitches to work the eighth and Glen Perkins struck out two in the ninth for his 11th save.
Minnesota struck for three in the first inning, two of them coming in on a double by Ryan Doumit. Aaron Hicks added his sixth homer of the season in the fourth.
All four runs came off Marco Estrada (4-3), who surrendered seven hits in seven innings.