DENVER -- The D-backs' six-game winning streak came to a crashing halt Tuesday afternoon at Coors Field.
The record book will show that the D-backs lost, 12-4, to the Rockies, but the truth of the matter is that they beat themselves with poor defense and too many walks.
The loss, in the first game of a day-night doubleheader, dropped Arizona to one game below .500. Since winning on Opening Day, the D-backs have had six chances to go over the .500 mark and have been unsuccessful each time.
"At the end of the game we kind of let the game get away from us with our sloppy play," D-backs manager Kirk Gibson said.
The day started off promising when the D-backs got on the board first with three runs in the third inning.
Xavier Nady drove in one of the runs with a groundout and Melvin Mora smashed a single off the glove of shortstop Troy Tulowitzki to drive in two more.
In addition, the Rockies lost starter Jorge De La Rosa, who was forced to leave the game in the third with an elbow injury that was later diagnosed as a ligament tear, jeopardizing his season.
The D-backs also left some potential runs on the bases, stranding five through the first four innings.
"We had three runs early, but we had more opportunities," Gibson said.
Josh Collmenter, who had yet to allow a run in 12 previous innings as a starter, gave up a pair of solo homers in the fourth to cut the Arizona advantage to 3-2.
One of the homers was to former D-backs farmhand Carlos Gonzalez, who would also hit a two-run shot in the seventh.
"He's difficult because his mechanics are a little different from anybody else," Gonzalez said of Collmenter. "He believes in his breaking pitches more than his fastball. His fastball is only, like, 87 or 85 [miles per hour], but it looks faster than that because his changeup is pretty good and his mechanics, his delivery, are difficult. The first [at-bat] he threw me a couple fastballs and I didn't see any breaking balls, so I was expecting something soft, and that's how I got him in the second at-bat."
Things would turn ugly in the fifth for the D-backs as an error by Nady at first and a pair of walks contributed to three unearned runs in the frame.
"Walked a run in, walked a leadoff guy, made an error, so we gave them some opportunities and they took advantage of it," Gibson said. "They did a good job of taking advantage of our mistakes."
Collmenter (3-1) wound up allowing five runs (two earned) on five hits over 4 1/3 innings.
"Just missed a few spots," Collmenter said. "Location was off today. It was something I had to struggle with. It wasn't just going out there and just being able to put it wherever you want it. I had to fight it a little bit today. Unfortunately it didn't work out quite as well."
That Collmenter had a pair of walks was somewhat of a surprise given that he had walked just one in his first 26 big league innings.
"I was able to throw a lot of strikes and pound the zone," Collmenter said of his previous outings. "And today I was behind in a lot of counts and had to make some good pitches to get out of it. I wasn't hitting the corners. I was able to keep them at bay for four innings and get through it."
The Rockies tacked on two more runs in the sixth off the Arizona bullpen thanks in part to another three walks, and piled on with five runs in the seventh to put the game on ice.