Gonzalez, who hit 57 homers last season, had two hits. Guillen had four, helping the Diamondbacks open a 10-5 lead through five innings.
Brian Anderson got the win despite allowing four runs and 10 hits in 3 2/3 innings. Veteran righthander Mike Morgan allowed two runs and five hits in 2 1/3 innings while minor leaguer Duaner Sanchez allowed three runs in the bottom of the ninth.
Milwaukee had 21 hits as center fielder Ryan Christenson and left fielder Geoff Jenkins had three apiece.
Ruben Quevedo (0-1) put the Brewers in an early hole by giving up six runs and five hits in three innings.