Todd Helton certainly picked a good time to hit his first home run of the season.

The Colorado first baseman's two-out, two-run blast in the bottom of the ninth inning sent the Rockies to an 8-7 win over Arizona in a rain-soaked game that lasted almost five hours, including a pair of rain delays.

Helton's seventh career walkoff homer, a moon shot blast down the right-field line, simultaneously ended a comeback bid by Arizona, which has dropped the first two contests of this three-game set. It also ended the active consecutive saves streak, held by J.J. Putz (0-1). He saved 28 in a row entering Saturday.

Tyler Chatwood (1-0) recorded the win by tossing two innings of relief, allowing one run on two hits and one walk with three strikeouts.

Colorado won its second straight and third in its last four.