With the game tied 3-3 in the bottom of the seventh, the Brewers jumped on relievers Esmil Rogers (0-1) and Edgmer Escalona for seven runs.
Rickie Weeks and Ryan Braun each ripped run-scoring triples and Carlos Gomez singled home a run before Gonzalez launched his shot for the Brewers, who evened their three-game series at one win apiece.
The Milwaukee shortstop finished 3-for-4 with four RBI.
Jose Veras (2-0) earned the victory with a scoreless top of the seventh.
Marco Estrada started in place of the injured Chris Narveson and held the Rockies to one run on two hits over five innings, striking out nine.
Drew Pomeranz limited Milwaukee to two runs on two hits over five innings for Colorado.
Troy Tulowitzki and Todd Helton homered for the Rockies.