The Astros again stumbled out of the gate, one season after losing 106 games.
Houston rallied from a two-run deficit to tie it in the fourth and the game remained deadlocked until a miscue by catcher Jason Castro brought home the go-ahead run in the eighth.
Young ran for Ramon Hernandez, who led off the eighth with a single against Fernando Rodriguez. Young stole second and when Castro tried to throw behind the runner on a pickoff attempt, the ball sailed into the outfield.
The speedy Young came all the way around to score and Colorado added an insurance run on Troy Tulowitzki's ninth-inning homer.
Tulowitzki also had a sacrifice fly during a three-run Colorado third that gave the Rockies a 3-1 lead. Carlos Lee and Brian Bogusevic hit solo homers in the fourth to tie it.
Starter Jeremy Guthrie gave up three runs on four hits over seven innings to get the win. Rafael Betancourt, taking over the Colorado closing role, put two runners on in the ninth before coming away with the save.