PHOENIX -- Austin Gomber gave the Rockies a second straight solid start, but for the second night in a row, the D-backs escaped with a narrow win against the Colorado bullpen.

Staked to a one-run lead in the ninth inning, rookie closer Victor Vodnik lost a two-out, bases-loaded battle against the red-hot Jake McCarthy, who sent a walk-off single into left field to give the D-backs a 4-3 victory and their 17th win in their last 20 games.

“A really good matchup of two young players,” Rockies manager Bud Black said. “McCarthy’s kind of settled in to being a guy the Diamondbacks are counting on, where he hit fifth in the lineup last night, hit second in the lineup today. He’s really swinging the bat great. And [Vodnik] has been throwing the ball really well, a rookie being thrust into the ninth inning and performing.

“Like I told Victor, no player is invincible, whether it’s McCarthy or Vodnik. But that was a good battle -- two strikes, 2-2 count and a 100 mph fastball up out over the plate and he put the bat on it.”

Black, a veteran manager who had 15 big league seasons as a pitcher, knows as well as anyone alive what the 24-year-old Vodnik had to have been feeling, so he had a private meeting with the right-hander after the game.

“He knows what it’s like, you know. He’s seen it. He’s been through it,” Vodnik said. “It feels good that he had my back, and now, I mean, I just have to let this one go and just keep going.

“It’s just frustrating, you know. Gomber did a great job and [Tyler Kinley] did, and so did Noah Davis. But hitters are pretty good, too, sometimes.”

Gomber, who was coming off a five-run, three-inning outing against the Mets, limited the D-backs to two runs on six hits and a walk over six innings, striking out four.

“It felt good,” Gomber said. “I was a little erratic at times, but I was able to make pitches when I needed to.”

The lefty also turned in his ninth straight start with one or zero walks, which has been a point of focus this season.

“When I walk guys, I’m going to have a hard time, flat out,” he said. “I’ve just made it a priority over my career, and been doing a good job of it this year just putting the ball in the strike zone, making guys earn their way on.

“You’re going to give up hits, but especially playing in Coors Field I think free passes come back to kill you.”

With Gomber’s effort coming on the heels of rookie Bradley Blalock’s impressive debut, this series has been a relative boon for the Rockies’ rotation, which had turned in only 24 1/3 innings in the seven games prior, the fourth-fewest over any seven-game stretch in franchise history.

“That was a game that, in my eyes, was a Gomber game,” Black said. “Six solid innings, a couple of runs, six hits, just the one walk, couple punchouts -- he threw the ball great.”

Unfortunately for the Rockies, they don’t have any wins to show for this two-game rotation renaissance. Monday’s setback came after the D-backs scored the tying and go-ahead runs on back-to-back wild pitches by Kinley in the seventh inning.

Kinley was able to bounce back on Tuesday with a 1-2-3 eighth inning, and Black was glad he was able to give the veteran right-hander that chance.

“All managers will tell you they want to get their guys back on the horse as quickly as possible,” Black said. “And if there’s a situation where you [show players you] believe in them and trust them and have confidence in them, it helps them long term.

“Tyler’s thrown the ball really well. He’s pitched pretty well over the last month, so for us it was very practical to get him back in there. We trust him. He’s one of the guys we’ve leaned on in the bullpen during his tenure here.”