DENVER -- Troy Tulowitzki is giving the Colorado Rockies some energy.
Tulowitzki started Colorado's comeback with a two-run homer, then singled home the winning run to cap a three-run rally in the ninth inning Thursday that led the Rockies over the Houston Astros 7-6.
"I only know one way to play, and that's to give everything when I'm in the lineup," Tulowitzki said. "I want to make every play and be a tough out on every at-bat."
Houston led 6-2 before Tulowitzki homered in the sixth off Roy Oswalt. The Astros were ahead 6-4 when Dan Wheeler (0-3), who had converted 10 straight save chances, took over from former closer Brad Lidge to start the ninth.
Kaz Matsui doubled leading off and scored on a single by Matt Holliday, his fourth hit of the game. Todd Helton lined the ball off the glove of left fielder Carlos Lee for a single, Garrett Atkins loaded the bases with a walk and Brad Hawpe tied the score with a sacrifice fly.
Tulowitzki hit a 1-2 pitch under the glove of shortstop Adam Everett, scoring pinch-runner Jamey Carroll.
"I fell behind in the count and didn't get down," Tulowitzki said. "I stayed with the pitch and got enough of it to get it out of the infield."
Tulowitzki leads NL rookies with 26 RBI.
"He's a good young player, he's exciting and he loves the spotlight," Colorado manager Clint Hurdle said of Tulowitzki. "He loves the big situation."
Jeremy Affeldt (3-1) pitched a scoreless ninth for the win. Wheeler blew a save for the second time in 12 chances.
Colorado's Josh Fogg, returning after a stint of the disabled list caused by a strained right groin, gave up six runs and 10 hits in five innings. He is 0-4 in his last six starts.
Oswalt allowed four runs and nine hits in six-plus innings.
"I was trying to get through seven or eight innings without using the bullpen," Oswalt said. "I got the pitch count and didn't throw great, but good enough to last."
Willy Taveras homered on Oswalt's third pitch of the game, Taveras' first home run in 349 at-bats since Aug. 4 against Tony Pena at Arizona.
"I played with Willie last year," Oswalt said. "He's got places where you can pitch to him, but I think he knew where I was going to throw him."
Adam Everett's RBI groundout tied the score in the second, and Houston went ahead 4-1 in the third on Lance Berkman's two-run homer and Luke Scott's RBI triple.
Colorado's Chris Iannetta had an RBI single in the fourth inning, but Brad Ausmus made it 6-2 with a two-run double to center over Taveras in the fifth.
"This is certainly a tough one," Houston manager Phil Garner said. "You feel like you've got it in the bag, the kind we're accustomed to winning, and we just didn't do it."
Houston 2B Craig Biggio took a scheduled day off from the lineup, but did pinch hit leading off the eighth and struck out against Manny Corpas. ... Houston manager Phil Garner plans to use Carlos Lee or Biggio as designated hitters for interleague play. ... Holliday has a career-best 15-game hitting streak. ... Colorado is 4-0-1 in its last four series and finished 6-4 on its homestand.