Milwaukee has lost 10 of its last 14 games but still lead the NL Central by one game over the Chicago Cubs, who lost 2-1 to the Houston Astros in 10 innings.
"Our attitude remains fine," said Geoff Jenkins, who went 2-for-3 for the Brewers. "We've lost some tough games the last couple of weeks, but we're still right there in the thick of things."
"I've been struggling of late and needed something like that," Hawpe said. "I got a good pitch and made a good swing to get it out of the park."
Vargas gave up six runs and 12 hits in seven innings. He struck out two and walked one in falling to 4-1 in his career against the Rockies. Chris Spurling pitched the eighth.
"With the state our bullpen is in, Claudio Vargas gave us a big-time game to get us through," Brewers manager Ned Yost said. "There's a lot of guys down there that didn't even pick up a ball, which is really good. A day off helps tremendously. Claudio and Spurling took care of that."
Fielder homered in the second but Holliday responded with a two-run drive in the bottom half.
Ryan Braun hit a one-out homer in the fourth for his 21st of the season for the Brewers.
Josh Fogg (6-7) went seven innings for the Rockies, allowing six hits and two runs. He struck out two and walked one.
"It was nice to get an outing like that from Fogg," Colorado manager Clint Hurdle said. "He worked his way out of some jams and didn't give up more than the two solo home runs."
Fogg improved to 9-4 in his career against the Brewers.
"I stayed within myself whenever I got into trouble," Fogg said. "And I made pitches and got outs when I needed them."
- Brewers OF Bill Hall sat out for the second straight game.
- Hawpe had been 2-for-21 and without an RBI over his previous seven games.
- Colorado optioned C Chris Iannetta and RHP Ramon Ramirez to Triple-A Colorado Springs and purchased the contract of C Edwin Bellorin and RHP Ryan Speier from its top farm club.