The struggling Houston offense was further depleted after the game when it was announced the Astros had traded all-star outfielder Hunter Pence to Philadelphia for four minor league players.
Houston had a rare two-game winning streak snapped and lost for the 71st time this season. The Chicago Cubs are next-worst in the majors with 64 losses.
Wolf (7-8) won for the first time in July, walking three and striking out five while throwing 117 pitches. Takashi Saito and Kameron Loe completed the shutout.
Milwaukee took the lead in the fifth when Casey McGehee and George Kottaras both singled in a run.
Corey Hart added a two-run single in the seventh.
Jordan Lyles (0-6) remained without a win in his major league career, giving up two runs on six hits in six innings. Lyles has made 11 starts in his rookie season.