ATLANTA (AP) — Ronald Acuna Jr. is only 20 years old, so he never gives much thought to his still-fledgling place in baseball history.There'll be plenty of time for that.So, it wasn't until Acuna got back to the Atlanta clubhouse after a long, brilliant day that he finally realized what a unique feat he had pulled off.Rarer, even, than a perfect game.Or an unassisted triple play.The brilliant Braves rookie joined a very exclusive club by hitting leadoff homers in both games of a doubleheader Monday, sparking first-place Atlanta to a sweep of the Miami Marlins.Acuna appears to be only the fourth player to go deep at the start of two games in a single day, joining Brady Anderson, Rickey Henderson and Harry Hooper.By comparison, there have been 23 perfect games and 15 unassisted triple plays."I just found out," Acuna said through a translator when asked if he knew about his unique double. "I give thanks to God for the opportunity to make history in my own sense."Acuna worked the count in his favor the first time up. Then he got hold a 3-1 pitch from Pablo Lopez , sending an opposite-field drive an estimated 414 feet into the Braves' bullpen in right-center.There was no waiting around in Game 2. On the very first pitch from Merandy Gonzalez, making his first big league start, Acuna launched a towering, 441-foot shot into the seats in left-center ."It's pretty special," said Braves star Freddie Freeman, who also homered in Game 2. "He's some kind of hot right now. What he's doing at the plate, you just don't see it very often."Over the course of about nine hours, Acuna went 5 for 8 with two homers, five RBIs, five runs, two walks and a stolen base.He's really flourished since moving into the leadoff spot right after the All-Star break, hitting .344 with 10 homers in 23 games.Acuna has 17 homers on the season, four of them leading off games. The franchise record for that category is held by Marquis Grissom, who had seven leadoff homers in 1996.Don't bet against Acuna taking down that record."Freddie and I were just kind of standing there smiling at each other like, 'Again?'" Braves manager Brian Snitker said. "It's been fun to watch."If anything, Acuna has exceeded the enormous hype that accompanied his brilliant performance in spring training, even though the Braves started him off at Triple-A to ensure they'll get an extra year before he's eligible for free agency.Since taking his rightful place in the big leagues, Acuna's been making up for lost time."We've been waiting for this kid since the start of spring training," said Mike Foltynewicz, who picked up the Game 2 win with eight strong innings. "We're happy as happy as hell to have him on our team. Every single night, he's going something. I don't know how you pitch to him leading off a game."The Elias Sports Bureau said Anderson was the last to hit a pair of leadoff homers in one day, going deep twice for the Baltimore Orioles against the Chicago White Sox on Aug. 21, 1999.Before that, it was accomplished by Henderson when the Oakland A's hosted the Cleveland Indians in a twin-bill on July 5, 1993. Then it takes a really deep dive into the record books — more than a century — to find Hooper going deep to start a pair of games for the Boston Red Sox against the Washington Senators on May 20, 1913.Acuna's hot streak couldn't have come at a better time for the Braves, who have won 12 of their last 16 to grab a one-game lead over Philadelphia in the NL East.With a month and a half left in the season, Atlanta is a serious playoff contender for the first time since 2014. That year, the Braves faded badly down the stretch and embarked on a major rebuilding job that led to three straight 90-loss seasons.Now, stocked with some of the game's best young talent, they're in the thick of things again.No one expects Acuna and the rest of the Baby Braves to be overwhelmed by their first pennant race."They play like their hair's on fire," Snitker said. "They're infectious kids. They rub off on all of us."___Follow Paul Newberry on Twitter at www.twitter.com/pnewberry1963 . His work can be found at https://apnews.com/search/paul%20newberry___For more AP baseball coverage: https://apnews.com/tag/MLBbaseball