Batting against Rob Scahill, Kozma grounded into a double play.
Corey Dickerson's RBI triple with one out in the bottom of the inning gave the Rockies a 7-6 victory in a marathon that lasted 5 hours, 9 minutes.
"He's a good sinkerball pitcher," Kozma said of Scahill. "Faced him a couple times in the minors. I was just looking for something to get up and drive. I had something to hit and didn't do anything with it."
What Kozma did was fire his helmet to the ground in disgust. He entered the game hitting just .218 but with a .324 average with runners in scoring position. It is rare for Kozma to show emotion, but this was not just any clutch situation.
"Game on the line," Kozma said. "The game lasts six hours or however long it lasted. Everybody was feeling something, especially at that point."
Charlie Blackmon finished with four hits and Troy Tulowitzki and Todd Helton homered for the Rockies in tying the second-longest game in Coors Field history.
Matt Holliday had three hits for the Cardinals, who had their NL Central Division lead over Pittsburgh trimmed to one game. The Pirates beat San Diego 10-1 on Thursday.
DJ LeMahieu started the winning rally with a one-out single to right. Dickerson then drilled a line drive into the right-field corner as LeMahieu rounded the bases. The relay from second baseman
Matt Carpenter beat LeMahieu but catcher Molina couldn't control the ball as LeMahieu crawled to touch home.
It was Dickerson's second triple of the game and sixth of the season.
In the first inning, Helton tagged out Carpenter at first with the hidden-ball trick. After Roy Oswalt threw to first, Helton feigned a throw back to the mound and tagged Carpenter when he stepped off the bag to end the inning.
The teams traded late-game rallies.
Helton, who struck out with the bases loaded to end Wednesday's game, turned on Edward Mujica's fastball Thursday, drove an 0-1 offering into the Rockies bullpen to lead off the ninth and tie it at 6-all.
It was Mujica's fourth blown save in 41 chances.
Holliday hit his former team hard, going 8 for 21 with a home run, four walks and four RBIs in the series. He reached base in six straight at-bats Thursday and was poised to be the hero with his RBI single in the ninth before Helton tied it with his 14th home run of the season.
It was part of a back-and-forth that saw the Cardinals rally from four runs down but blow two late leads.
Trailing 4-0, the Cardinals got within a run in the fourth. Oswalt walked the first two batters, Carlos Beltran singled to score
Jon Jay and Holliday came home on a sacrifice fly.
Tony Cruz doubled off the wall in left to make it 4-3.
Holliday tied it at 4-all with an RBI single in the fifth.
David Freese gave the Cardinals a 5-4 lead in the eighth with an RBI double to center, but Colorado tied it in the bottom of the inning on Dickerson's two-out triple.
Helton helped the Rockies take an early lead with a leadoff double in the second, his 588th career two-bagger. He moved to third on Charlie Culberson's infield single and scored on Yorvit Torrealba's blooper to right.
Culberson scored on a double play to make it 2-0.
Tulowitzki's two-run homer in the third made it 4-0. It was his 23rd of the season.
Michael Wacha had a curious Coors Field debut. He allowed four runs and 12 hits but no walks with seven strikeouts in 4 2/3 innings.
"Plain and simple, I gave up too many hits," Wacha said. "And I didn't put our team in a good position to win a game. I feel it all starts with the starting pitcher, and I just wasn't able to get guys out there for a while and gave up entirely way too many hits."
NOTES: Cardinals 1B
Matt Adams (right elbow soreness) did not start but came into the game as a defensive replacement in the eighth. He singled in the ninth and was replaced by a pinch-runner. ... Rockies OF Michael Cuddyer (left wrist, forearm) was out of the lineup but hopes to play Friday. ... RHP Shelby Miller (14-9) will open the Cardinals' weekend series in Milwaukee on Friday. ... RHP Jhoulys Chacin (13-9) will start the first game of Colorado's series against Arizona on Friday.