Credit two of the Braves’ prized young players – two players who came into the organization together in the 2015 amateur draft -- for Wednesday night’s victory over St. Louis at SunTrust Park.

Mike Soroka, the Braves’ second pick of that draft, pitched seven scoreless innings, and Austin Riley, their third pick, hit a long home run in his major-league debut.

They were the headliners of the Braves' 4-0 win over the Cardinals, with strong supporting contributions from Charlie Culberson, who hit a two-run homer after entering the game as an eight-inning defensive replacement for Riley in left field, and Luke Jackson, who recorded a six-out save.

Riley’s home run – a 438-foot solo shot deep into the left-center field stands in the fourth inning – reminded Braves manager Brian Snitker of another rookie who famously homered in his Atlanta debut.

“I remember when Jason Heyward hit his first one off (Carlos) Zambrano,” said Snitker, referring to Heyward’s first career plate appearance on opening day 2010.  Snitker was the Braves’ third-base coach at the time. “I remember I came in (the dugout), and Bobby (Cox) was, like, ‘You think he wasn’t going to do that?’ ”

Of Riley’s home run Wednesday night, Snitker said: “I was kind of expecting that to happen, really.”

The home run, belted with an exit velocity of 109.1 mph off an elevated 2-1 fastball from Cardinals starter Michael Wacha, came in Riley’s second MLB plate appearance. He became the eighth player in the Braves’ Atlanta history to hit a home run in his first major-league game.

“I’m speechless, I guess you could say,” Riley, 22, said afterward. “I can’t be happier. … It was a dream-come-true.

“I never would have guessed I’d hit a home run in my debut. It’s awesome.”

Yet the home run continued a recent pattern for Riley, who had hit 13 homers in his past 18 games for Triple-A Gwinnett before being summoned to Atlanta late Tuesday night. He finished his first big-league game 1-for-3 and caught the only fly ball hit to him in left field.

Riley admitted to some nervousness in his first at-bat, when he struck out on a changeup.

“I got in the box, and I could feel my left foot kind of shaking a little bit,” he said. “I was, like, just got to breathe.”

His next at-bat, he got his first big-league hit, first home run, first RBI, first run scored.

“He’s going to be a great addition to our team,” Culberson said. “I think Braves fans are going to be very excited to watch him for a long time.”

“He’s amazing,” Soroka said of Riley. “We all know that. We all saw his stats in the minors. I’ve been growing up with him, really, since we were drafted.

“I got the tingles when he hit that (home run), just because we knew it right off the bat. I was thinking about it so much I almost missed my next at-bat.”

Soroka, 21, held the Cardinals to three hits, improving his record to 4-1 and lowering his ERA to 0.98. He has held opponents to one earned run or fewer in each of his six starts this season and in nine of his 11 career starts.

“To be that young -- I mean, I was trying to get out of A ball (at that age) -- and he’s dominating in the big leagues,” Culberson said of Soroka. “He’s next-level.”

“He has lights-out stuff,” Riley said, “and he has been proving it since (Class A) Rome.”

Soroka’s most difficulty came in the third inning, when he uncharacteristically walked two batters and hit another with a pitch. But a double play got him out of a bases-loaded jam.

As this game reflected, the 2015 draft is serving the Braves extremely well.

They selected pitcher Kolby Allard, now at Gwinnett, with their first pick (No. 14 overall) of that draft. Then they took Soroka with the 28th overall selection (a compensation pick from the Twins for their signing of pitcher Ervin Santana as a free agent) and Riley with the 41st selection (a competitive balance round pick obtained from San Diego in the Craig Kimbrel/B.J. Upton trade).

As the Braves lined up for the national anthem before Wednesday’s game, Snitker was reminded again of the array of young talent on his team.

“I was looking down that line at all those young players, and I was, like, ‘Man, you forget,’ ” Snitker said. “When you see them all bunched up together, (you remember) how young they are, how talented they are.”