PHOENIX -- The Arizona Diamondbacks seem more comfortable when the game is on the line in the late innings, and they showed it again Saturday night.
Cody Ross' sacrifice fly to deep left-center field drove in A.J. Pollock and gave the Diamondbacks a 3-2, 10-inning victory over Colorado, keeping Arizona perfect in extra-inning games at 6-0.
"It's definitely nice to be on this side of it. I had my fair share of walk-off losses last year," said Ross, who signed a three-year, $26 million deal this winter after spending 2012 with Boston.
"It's definitely something that you have to have if you are going to plan on playing down the stretch and into the playoffs. You have to win the close ones, and you have to win the walkoffs and the one-run games on the road, too."
A.J. Pollock opened the ninth off Edgmer Escalona (1-1) with a single to left field, his third hit of the game, and stole second base on the second pitch to Miguel Montero with one out.
Pollock took third when catcher Wilin Rosario's throw went into center field and Montero was intentionally walked to bring up Ross, who also tripled in a run in a two-run first.
"You've seen us before in bigger situations than we were in tonight. A quality at-bat. Good approach. Good execution. Cody was able to barrel one," Arizona manager Kirk Gibson said of Ross, who was the MVP of the 2010 National League Championship Series while with San Francisco.
The Diamondbacks (14-10) have won eight games in their last at-bat and have played a major league-high 17 games decided by two runs or fewer. Four of their last five victories have been in extra innings.
Pollock hit his third homer of the season in a two-run first, his first homer since he had two and a double while driving in six runs in Arizona's 10-2 victory over Pittsburgh on April 10.
J.J. Putz (2-0) pitched a 1-2-3 10th after saving the first game of the series on Thursday.
Rosario's sixth home run of the season and second in as many games broke the Arizona shutout in the sixth and made it 2-1. Rosario had three hits.
The Rockies tied it at 2 in the seventh when Dexter Fowler doubled and scored on Troy Tulowitzki's two-out single off Heath Bell. Tulowitzki was 1 for 18 against Bell before that at-bat.
Colorado (15-9) left eight men on base, was 1 for 9 with runners in scoring position an had two runners caught at second base after two singles to open the eighth.
"You miss that many opportunities, it's going to come back to haunt you," Colorado manager Walt Weiss said.
Colorado (15-9) has lost five of its last seven games but still has an one-game lead in the NL West.
Diamondbacks starter Wade Miley walked a career-high seven in 4 1/3 innings, including four in the fourth.
"You don't get the big hit and we didn't. We had a lot of opportunities to get it, but we just didn't come up with it," Colorado outfielder Michael Cuddyer said.
NOTES: Arizona shortstop Didi Gregorius, struck in the head by a Josh Outman fastball in the seventh inning on Friday night, passed cognitive and CT tests that night but was not cleared to play Saturday, Gibson said. "I don't think I would be close to normal right away," Gregorius said when asked his condition. "Probably take a couple of days, I think." He said he held no malice toward Outman. "I don't think he did it on purpose, so everything is good, everything is fine. There was obviously no reason. I already had two strikes," Gregorius said, ... Weiss said the pitch just got away from Outman, who was intending to throw it low and outside. "That's always really tough to see. I have a lot of respect for the career of every player in the league. We are all very sensitive to that. You never want to see a guy get hit in the head," Weiss said. ... Arizona outfielder Jason Kubel (quadriceps) was 3 for 4 with a home run in an extended spring game on Saturday. Kubel is eligible to return from the disabled list on Monday, but the plan is to send him to Class AAA Reno on a rehab assignment Monday and Tuesday, with a target return date of Wednesday. "It could change if something happened with an injury or something," Gibson said. "He's kind of ready, but we 'd like to send him out and kind of confirm that." Kubel is hitting .333 with two homers in eight games this season.