ST. LOUIS -- Austin Riley was trying to decipher whether the home run he had hit a few hours earlier was the longest he had ever launched a baseball.

“I hit one in Charlotte. We don’t know how far it went, but it went over that scoreboard,” Riley said. “Between those two, those are definitely two of my furthest. Those are the ones you don’t feel coming off the bat.”

In the top of the first inning of the Atlanta Braves’ 8-4 win over the Cardinals on Monday night, Riley got a 93.3 mph fastball from Jake Woodford in the heart of the strike zone and hit it flush. His 473-foot home run was the longest home run hit at Busch Stadium in the Statcast era (since 2015) and cleared the left-center field stands on the fly.

• Longest home runs of 2023

Riley’s bat, by the way, a Marucci AP5 maple model, was designed for Albert Pujols, who smacked 122 of his 703 career home runs at this version of Busch Stadium. Riley, who is 6-foot-3 and 240 pounds, launched 38 long balls last season, but none quite as majestic as Monday’s moon shot.

“That was a big man hitting it a long way right there,” Braves manager Brian Snitker said.

Riley’s homer, the first of his season, was struck with an exit velocity of 113.3 mph and a launch angle of 28 degrees. It was the second-longest home run hit so far this season after a 485-foot shot by the Yankees’ Giancarlo Stanton on Sunday.

It could be the first of many notable home runs for this team in 2023. The Braves, who hit more homers than any team aside from the Yanks last season, kept the hard hits coming in the second, when Ozzie Albies and Ronald Acuña Jr. each homered.

Albies’ home run -- the 99th of his career -- eked over the right-field wall. It was a promising sign considering the majority of Albies’ power typically comes when the switch hitter is batting right-handed. Coming into Monday, Albies had a .561 career slugging percentage vs. lefties and a .436 slug vs. righties.

“We’re a pretty dangerous offense, too,” Snitker said. “I like how deep our offense is. It’s kind of what we’ve been accustomed to.”

Acuña’s blast to center followed an Orlando Arcia double and gave Atlanta a five-run lead before the Cardinals had batted for a second time. Monday night was the kind of game that could jump-start Acuña’s season. He was on base in four of his five plate appearances, finishing a triple shy of the cycle.

The Braves are expecting big things from their superstar right fielder now that he is fully healed from a major knee injury in 2021 that they think contributed to a sub-par (by his standards) .764 OPS in 2022.

“It’s completely different. I feel like last year I would have similar swings and I wouldn’t get the same result, whether it be a homer or whatever,” Acuña said through an interpreter. “Now, it feels like I have the strength that, if I put the swings on it that I want, I get the results that I want.”

A series of new rules that went into effect this season were geared, in part, at encouraging higher-scoring games, and the Braves seem to have gotten the memo. Ten Atlanta batters into the game, the Braves had managed to score six runs on seven hits. Already, the Braves have hit seven home runs in just four games of 2023.

The Cardinals showed signs of doing early damage themselves, but Charlie Morton was able to limit damage with the help of Arcia, who made a diving catch on a Jordan Walker line drive in the second inning that was traveling 107.7 mph.

St. Louis, which also has a deep lineup, added two more runs off Morton in the fourth after hits from Nolan Gorman, Tyler O’Neill and Walker, a 6-foot-6 rookie outfielder who went to high school in Decatur, Georgia, just outside Atlanta.

Morton, looking to return to 2021 form after a mediocre 2022, worked around nine hits to hold the Cardinals to three runs over 5 1/3 innings. He struck out just one batter and allowed two walks.

“I thought he was really, really good,” Snitker said. “He got into the sixth inning. He hadn’t pitched for a while, and that’s not an easy lineup to navigate either, so I think he did a really good job.”

The Braves have opened the season without closer Raisel Iglesias, who is dealing with shoulder inflammation on the injured list. But they have yet to have a save situation in part because their lineup has produced seven or more runs in three of their four games so far. Three Atlanta relievers protected the big lead their offense staked them to, with A.J. Minter -- who figures to get save opportunities with Iglesias out -- pitching a scoreless ninth to hold the four-run lead.