Tulowitzki's RBI double in the ninth inning put the Rockies ahead in their 3-1 victory over the Diamondbacks on Tuesday night at Chase Field in front of 23,058.
Of Tulowitzki's 20 RBIs this season, eight have either tied games or put the Rockies ahead.
"I definitely like being in those situations, to put us ahead or win a ballgame," Tulowitzki said. "I've always wanted to be the guy up."
Tulowitzki's double off Brandon Lyon (3-2), which followed a Garrett Atkins leadoff walk and later was followed by a Ryan Spilborghs sacrifice fly, helped the Rockies win for just the fifth time in 14 games.
The Rockies' formula of '07 -- good pitching but equally good pitching from the opposition and an inability to produce in the clutch -- seemed intact Tuesday, before Tulowitzki changed the result.
"He's got great desire," Rockies manager Clint Hurdle said. "You expect that out of young players being up here, but he has a special want-to, and he never thinks he's out of an at-bat. He never thinks he's out of a play in the field and he's looking to make a difference when he's out on the bases."
Veteran Todd Helton, who knocked two doubles, said of Tulowitzki: "He plays hard and plays right. He's going to be really, really good."
Now what the Rockies are hoping to change is a 2-6 record in series-deciding games. The teams meet again Wednesday night.
The Rockies had gritty pitching from Josh Fogg, who pitched around six hits and four walks in six innings before he left the game with a left groin strain.
But they also ran into hot D-backs starter Livan Hernandez, who fanned eight to work around nine hits in eight innings.
Hernandez picked off Helton after a leadoff double in the sixth, worked Willy Taveras into a groundout to end the seventh with a runner at second, and struck out Brad Hawpe after Helton doubled with two down in the eighth.
In addition to Tulowitzki's cool, the Rockies had a smooth bullpen performance. Relievers had absorbed the Rockies' previous three losses, including Monday in the series opener, and injuries and inconsistency have been hallmarks of the relief staff.
LaTroy Hawkins, in his return from a forearm strain, threw a perfect seventh inning, Many Corpas (1-2) walked one and struck out two in the eighth, and Brian Fuentes struck out one in a perfect ninth for his 12th save.
"[When] we get the healthy people back and get some continuity and some stability, we expect that to happen," Hurdle said.
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The only damper was the injury to Fogg when he bunted to advance Yorvit Torrealba in the seventh.
Fogg forced two double-plays. The bigger one ended the second, when Stephen Drew grounded out with the bases loaded. The only run came in the second, but Fogg ended the inning with two on base, and for the game, caused the D-backs to strand seven.
"I had a few more hits than I'd like and a few more walks than I'd like, but wiggling out of jams is something I've been able to do for the most part my last three times out," said Fogg, who has a 2.66 ERA in his last three starts.
Fogg isn't sure if the injury will cost him a start, but he'll find out more Wednesday. His condition could affect righty Taylor Buchholz (2-2, 5.94), whom the Rockies had planned to skip Friday against the Giants.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.