With the Rangers up, 7-5, the Cardinals had two on and two out in the bottom of the ninth inning and third baseman David Freese at the plate.
With a 1-2 count -- and the Rangers just one strike away from their first World Series title in franchise history -- Freese laced a 98-mph fastball from Rangers closer Neftali Feliz deep to right field, where it just eluded the grasp of Cruz as he retreated toward the wall.
"It went over my head," Cruz said. "He hit it pretty well. I thought I had a shot when he hit it and it kind of took off."
The two-run triple tied the score and sent the game to extra innings, in which the Cardinals overcame a two-run home run by Josh Hamilton in the 10th before winning it in the 11th when Freese played the hero again with a walk-off home run to center field off Mark Lowe.
"Cruz gave it a valiant effort," Texas manager Ron Washington said. "[Freese] hit a line drive. If it had some hang time to it, it might have been different. He smoked the ball, just hit it off the wall. [Cruz] got close to it but not close enough, undoubtedly, because he didn't catch it."
Cruz was later lifted after his final at-bat -- a flyout to right field in the 11th off eventual winner Jake Westbrook -- having strained his right groin. He did not take his position in the bottom of the inning, as left fielder David Murphy moved to right field, and Esteban German, who grounded out as a pinch-hitter in the 11th, occupied left.
"I didn't want to take the chance and run him back out there," Washington said immediately following the game. "I haven't had anything from the medical department as to the seriousness of it, but we'll just have to wait and see how everything is tomorrow."
Cruz maintained optimism. "I'm a little tight, but I'll be ready for tomorrow," he said.
Cruz was penciled in the lineup Friday for Game 7, though the Rangers said he would test his groin in batting practice to make sure he was capable of playing.
If he can play in Game 7 on Friday, Cruz will have a chance to set a new record. His home run in the seventh inning -- the second of back-to-back jacks with third baseman Adrian Beltre off right-hander Lance Lynn -- gave the Rangers a 6-4 lead and appeared to put a dagger in St. Louis. It did not.
It was Cruz's only hit in a 1-for-6 evening, but it tied him with San Francisco's Barry Bonds (2002) and Houston's Carlos Beltran (2004) for most homers in a single postseason.
Among players with at least 100 career postseason at-bats, Cruz's 8.29 at-bat-per-home run ratio is the best all time, eclipsing Babe Ruth's 8.60. According to the Elias Sports Bureau, Cruz's 14 postseason homers in 2010-11 are the most in consecutive years, surpassing Cleveland's Jim Thome (10 from 1998-99).
In this World Series, Cruz is batting .238 with two home runs and three RBIs.
Chris Haft is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.