Campos escaped a threat in the bottom of the seventh inning. But after Milwaukee scored twice in the top of the eighth to tie it, he took his second loss of the spring.
The winner was Jose Jimenez, who allowed the Brewers to tie the game. Elio Serrano worked a 1-2-3 ninth for the save.
An RBI single by Eddie Perez and an error by right fielder Luke Allen allowed the Brewers to score twice in the eighth.
Former Brewer Jose Hernandez had a two-run homer off Pascual Coco in a three-run fifth that gave the Rockies a 4-2 lead.
Keith Ginter homered in the first as Milwaukee scored twice off starter Nelson Cruz, who gave up five hits in three innings. Colorado got back one in the bottom of the frame off Glendon Rusch, who gave up four hits and three walks in four innings.