Young Brazilian tennis sensation Joao Fonseca had hundreds of fans at Arthur Ashe Stadium singing in chorus to celebrate his 19th birthday at the US Open. The moment came after a special exhibition match in which he featured alongside tennis legend Juan Martín del Potro, facing off against Andy Roddick and American NextGen, Alex Michelsen.After clinching a thrilling 11-9 match tie-break victory, the announcers informed fans about Fonseca's birthday and asked everybody to sing the birthday song in chorus. Here's a video:As of mid-August, Joao Fonseca has become the top-ranked Brazilian player before even getting into his 20s. He has made a huge jump in the ATP rankings, occupying the 44th spot in the world currently. Moreover, he became the youngest Brazilian to win a title in the Open era after capturing his first ATP Tour singles title at the 2025 Argentina Open.Joao Fonseca made a promising Wimbledon debutEarlier in July, Joao Fonseca made his debut at the All England Club and created history. He became the youngest male to reach the third round since 2011. His run ended with a hard-fought loss to Nicolás Jarry in four sets (6-3, 6-4, 3-6, 7-6(4)). Now, at the US Open, he'll start his promising campaign with a match against Miomir Kecmanović in the first round.Seeing Joao Fonseca's growth, renowned coach Rick Macci made a bold prediction about his future. According to Macci, the "chosen one" could challenge the likes of Jannik Sinner and Carlos Alcaraz in the near future.“Fonseca is the best young talent I’ve seen. He would be, to me, the chosen one that could be in there,” Macci said. "But he’s a couple years away, even though he could be top 20 by the end of the year, I think. And you gotta remember, as everybody is getting better, so is Sinner and Alcaraz, they’re gonna push themselves to add more sprinkles to their game. They’re just a cut above because of how complete they are."Fonseca has also been named in the squad of Team World for the 2025 Lavar Cup, where he'll join the likes of Taylor Fritz, Ben Shelton and Tommy Paul to play under tennis legend Andre Agassi.“I'm thrilled to have been selected to play with the Rest of the World in this Laver Cup," Fonseca said. "I've watched the tournament since I was a kid and have always dreamed of playing in it. Being on a team with Fritz, Paul, and Shelton, and being coached by Andre Agassi, is incredible. I'll give it my all.”It's not only on the court that Joao Fonseca stands out. On Instagram, he recently became the youngest tennis player to reach 1 million followers.