The damage was done in the eighth inning, when with the bases loaded and no outs, Bobby Abreu hit a two-run single to right field, scoring Jeff Mathis and Erick Aybar to provide the final margin.
"We just created a half an inning for them, and when you are in a 3-2 game and trying to hold on and win like that, you can't create opportunities for the opposition, and that is exactly what we did," said Rockies manager Jim Tracy.
In the eighth, the Angels didn't hit a ball out of the infield until Abreu's single. The inning began with a walk to Mathis, before two bunts -- one for a single by Aybar, and Chone Figgins' fielder's choice.
On the first, third baseman Ian Stewart looked toward second to check the lead runner before throwing to first, but Aybar beat the throw.
Figgins bunted a ball to the pitcher's mound, but even though Ubaldo Jimenez's threw to third ahead of lead-runner Mathis, Stewart couldn't get his foot on the bag in time.
"Off the bat I broke forward and didn't have time to get to the bag," Stewart said. "I just lost the bag and don't even know how far from it I was. I just messed up."
Jimenez threw seven-plus innings, four runs on seven hits.
In the eighth Tracy never thought of taking Jimenez out against Abreu, believing his fastball, which was still reaching 96, 97 mph, was good enough to get Abreu out.
"He really is a tough-luck loser tonight," Tracy said. "He pitched terrific."
The Rockies knocked Angels starter Sean O'Sullivan out in the sixth inning after a Troy Tulowitzki two-run home run off the left-field foul pole, Tulowitzki's second of the night for his first career multihomer game. His first home run came leading off the fourth inning on a 1-0 count after a pitch buzzed behind his head.
Tulowitzki's two home runs and three RBIs were the extent of Colorado's offense on Tuesday, in stark contrast to Monday night's 11-1 waxing of the Angels.
The Rockies also had missed scoring opportunities, when in the third inning with runners on first and second with no outs, they couldn't plate a run.
Managing six hits during the game, four Rockies had one hit, including designated hitter Brad Hawpe and first baseman Todd Helton.
"We hit a lot of balls hard," Tracy said. "Hawpe's 1-for-4 tonight was the hardest I have ever seen -- hitting the ball as hard as he did."
Angels closer Brian Fuentes, a former Rockies closer, worked the ninth, giving up no hits to secure the win. For Fuentes, it was his 20th save of year.
With such a tough and uncharacteristic loss in the books, the Rockies clubhouse was eerily quiet after the game.
"This is the first time in this long streak that we beat ourselves," Tracy said. "We realize what happened tonight, and nobody feels good about it. We just have to be able to wash it out and come back tomorrow."