Peralta timed the throw from Rockies catcher Michael McKenry back to reliever Rex Brothers and bolted for home.
Brothers leaped for the lobbed throw but couldn't come down with it cleanly. Peralta slid safely into home.
"[Players on the bench] just told me, 'Do it, do it. Don't be afraid. Do it,'" Peralta said. "I'm like, 'OK, I'm going to do it.'"
Said McKenry: "I just tossed it on back without truly paying attention."
Peralta said he had never stolen home before at any level, so Friday was a special first for him as he scored the D-backs' final run in a 5-3 series-opening victory against the Rockies at Chase Field.
The pair of Peralta-produced seventh-inning runs secured the victory for rookie Chase Anderson (7-4), who continued the hot streak he has been enjoying on the mound.
Anderson pitched six strong innings, giving up only one run -- a solo homer to McKenry. Anderson otherwise befuddled the Rockies, striking out six batters, walking one and scattering four hits.
"It's huge, especially to get the team off on the right foot, just to go out there and do my job, get the team deep in the game and let the hitter's take care of the rest," Anderson said.
The biggest trouble Anderson ran into on Friday came when he was at the plate. He was jammed by a ball he hit in his first at-bat, hurting his thumb.
Manager Kirk Gibson said he was worried Anderson would not be able to work his curveball after the injury, but said after the game that he threw some good pitches the next inning.
"I don't know if he was being coy about that," Gibson said, "but he got jammed pretty good and did a good job getting through that."
Anderson had an early cushion to work with thanks to his catcher. Miguel Montero gave the D-backs a 3-0 lead in the first inning with a three-run homer -- his 12th of the season and first since June 28.
"[Rockies pitcher Tyler Matzek] throws him kind of a hanging breaking ball his first at-bat with a couple guys on, and he picks up [Mark] Trumbo," Gibson said. "He's really done a good job of that this year."
Anderson handed his bullpen the lead after leaving the game after the sixth inning, and the first few relievers picked up the slack. Oliver Perez, Evan Marshall and Brad Ziegler combined for two scoreless frames, giving the game over to closer Addison Reed in a non-save situation.
Reed struggled, giving up a triple to pinch-hitter Brandon Barnes, who scored on an infield single by Corey Dickerson.
With the lead down to three runs, things got tricky.
Reed threw a wild pitch, and Dickerson took off for second. Montero corralled it but threw the ball into center field, allowing Dickerson to take third. Dickerson came around to score on a single, and after another hit, the Rockies had the tying runs on base.
Against Charlie Blackmon, though, Reed settled down, striking him out to end the game.