"That's a team I'm going to face during the season," Peralta said, "so I don't want to show them too much. I just wanted to locate my fastball and throw a little more changeups."
Peralta is among a slew of Brewers under the weather, but said it didn't impact his work on the mound. The ground-ball outs were just what he was looking for.
"Especially in the park we play, Milwaukee," he said. "If the strikeouts come, it's fine. If not, I'm happy with the result."
The Brewers spotted their starter a lead in the bottom of the first inning, when Aramis Ramirez delivered a two-run double that struck the left-center-field wall on a fly. Carlos Gomez scored the second of the runs all the way from first base.
The Rockies got on the board in the fourth when Drew Stubbs launched a solo homer off Tyler Thornburg. With the Brewers leading, 4-1, infielder Trevor Story moved the Rockies closer with a two-run home run in the seventh inning off Milwaukee's Michael Blazek.
Rockies starter Gus Schlosser took the loss after allowing two runs on four hits over two innings.
"It was good to bounce back [in the second inning]," Schlosser said. "Made some mistakes today, didn't have much of a breaking ball. That hurt me. I was able to bounce back in the second inning, get some weaker contact."
The victory was the Brewers' third in a row after losing their first five Cactus League games.
Up next for Brewers: Mike Fiers will be on the mound when the Brewers travel to Peoria, Ariz. to play the Mariners in a game that can be seen live on MLB.TV. Left-hander J.A. Happ starts for Seattle at 3:05 p.m. CT.
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.