Sheets (3-0) gave up just two hits and struck out four before leaving with tightness in his right arm. Four relievers combined to make Sheets the winner and Eric Gagne escaped a ninth-inning jam to pick up his fifth save.
Milwaukee, winners for the fourth time in six games, got two hits and a run each from Craig Counsell and J.J. Hardy.
The Reds lost for the sixth time in seven outings.
Bronson Arroyo (0-2) gave up five runs on eight hits over 5 2/3.
Hall's homer made it 4-0 in the third.
Gagne came on in the ninth with one run already in and gave up a run-scoring infield single to Edwin Encarnacion. But Gagne struck out the next two batters to end the game.