Baker homered and scored three runs and Quintanilla went 2-for-3 with two RBIs as the Rockies beat the Cleveland Indians on Wednesday night 4-2.
Jeff Francis (3-6) pitched into the seventh and gave up one earned run to earn his second win in his last four starts. Aaron Laffey (4-4) lost for the first time since May 22 and for just the second time since April 28.
Brian Fuentes pitched the ninth for his 12th save in 15 chances.
Quintanilla and Baker have been getting more playing time at shortstop and second base, respectively, because of injuries to Troy Tulowitzki and Clint Barmes. With those players expected back within a week, Baker and Quintanilla are showing they belong in the mix.
"They're playing well, and that's what you want," Rockies manager Clint Hurdle said. "The more good players you have on the team the better your chances are of winning. They're making the most of their opportunities."
Baker, who hit an inside-the-park home run in Tuesday's game, got the Rockies on the board first in the second inning. He hit a one-out double to left, Chris Iannetta was hit by a pitch and Quintanilla doubled down the right-field like to make it 1-0.
Baker led off the fourth with his third home run to make it 2-0.
"I'm not doing much different. My approach is the same and my stance is the same," Baker said. "The more at-bats you get the more comfortable you feel at the plate."
Francis cruised through the first five innings, allowing just three hits and no walks.
"I don't think I did a lot of things differently than I've done," he said. "It's amazing how a couple of things go your way in the first couple of innings, a double play, a line drive right at an outfielder, the next thing you know it's the fourth, fifth inning."
The Indians got to Francis in the sixth when Jamey Carroll doubled home Grady Sizemore with one out. The Rockies got the run right back in their half of the sixth when Baker reached on a fielder's choice, stole second and scored on Quintanilla's single to left to make it 3-1.
Shin-Soo Choo's sacrifice fly in the seventh inning trimmed the lead to one, but for the second inning in a row Cleveland had three base runners but managed to push across just one run.
"We put up some good at-bats, but had little to show for it in the sixth and seventh," Indians manager Eric Wedge said.
Francis pitched out of the jam in the sixth, and Jason Grilli worked out of trouble in the seventh.
"We are hitting the ball good and getting opportunities. We're just not getting the big hit," Carroll said. "Some of it has been their pitchers have made the pitches when they needed to.
The Rockies capitalized on Cleveland's lack of clutch hitting and quickly made it a two-run cushion. Willy Taveras led off the seventh with a single, stole second, moved to third on catcher Kelly Shoppach's throwing error and scored on Ryan Spilborghs' sacrifice fly
The Rockies have won 10 of their last 14 and clinched their fifth straight series with Wednesday's victory.
"Every time we start a series, that's what's brought up -- try to win the series," Baker said. "That's what we did last year toward the end and it worked out for us."
Cleveland RHP Fausto Carmona (left hip strain) experienced soreness after throwing a simulated game Monday and will not throw scheduled rehab games of June 20 and 25. Indians trainer Lonnie Soloff said Carmona will be shut down for three days and be re-evaluated after that. ... The Rockies agreed to terms with LHP Christian Friedrich, the team's first-round pick in this year's draft. ... Laffey's single in the third inning was his first major league hit.