SAN FRANCISCO -- A glance at Alex Young’s dossier gathered at the Arizona Diamondbacks’ Triple-A Reno affiliate suggested that a Major League environment might be too challenging for him.

He alternated between starting and relieving, indicating that he wasn’t efficient enough in either role to secure a steady gig. He never pitched more than five innings in any of his starts. And his overall ERA was an inflated 6.09.

Yet here was Young on Thursday night, standing atop the mound at Oracle Park and looking as if he were born to pitch there. His comfort was apparent as he limited San Francisco to one run and three hits in five-plus innings. The D-backs prevailed, 5-1, making Young a winner in his Major League debut.

“I’ve prepared myself my whole life for this,” said Young, who received this opportunity through a series of injuries and ineffective outings endured by previous D-backs starters.

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Anyone believing that Young had no business starting this game had company. The D-backs informed him late last season that he was being converted from starting to relieving. As he related, they told him “there are more opportunities for you” as a reliever.

“I kind of said to myself, ‘OK, this is what my role is now,’“ he said.

Fortunately for Young, Arizona’s hierarchy remembered him when they searched for internal starting help this year.

“I’ve waited my turn,” he said.

In the hours before the game, when anxiety could have overwhelmed him, Young calmed himself by contemplating his experiences at the College World Series with Texas Christian University.

“Those are intense games, so I reminded myself of that,” he said.

Young fended off the Giants by relying mostly on a combination of curveballs and cut fastballs. He no-hit San Francisco for three innings before Brandon Belt homered leading off the fourth. Brandon Crawford’s one-out double in the fifth inning proved harmless.

“He responded to every challenge,” D-backs manager Torey Lovullo said.

Young received help from airtight defense. In the fourth inning, for example, right fielder Adam Jones ran hard and long to snare Buster Posey’s drive to the right-field corner.

“If that ball’s not caught, who knows what happens,” Lovullo said. “Those are the hidden things ... that help win a ballgame.”

Lovullo felt compelled to remove Young after he surrendered Donovan Solano’s single and walked Belt to begin the sixth.

“Even though I felt like he was in total control of this outing, I didn’t want it to slip away from him,” Lovullo said.

Lovullo was at once respectful and circumspect when asked whether Young will receive another chance to start. Not counting the All-Star break, the D-backs have four scheduled off-days in July, which gives them room to skip a starter or two.

“He did everything he needed to do to get another opportunity,” Lovullo said.

Homers by Nick Ahmed in the fifth inning and Carson Kelly, who hit a two-run drive in the seventh, fueled most of Arizona’s offense.