Joao Fonseca defeated home favourite Francisco Cerundolo in straight sets in the Argentina Open final on Sunday, becoming the first 2006-born player to win a title on the ATP Tour.
The 18-year-old Brazilian won 6-4, 7-6(1) against World No. 28 Cerundolo, his fourth Argentine opponent at the ATP 250 event in Buenos Aires. He had to save two match points during his semifinal win over Mariano Navone.
Against fifth seed Cerundolo, who was chasing his fourth career title, World No. 99 Fonseca twice unsuccessfully served for the match but regrouped to claim victory in the tie-break in a frenzied atmosphere on Court Guillermo Vilas. He is the youngest South American and 10th youngest overall to win an ATP Tour title since 1990.
Fonseca’s first ATP Tour title comes exactly a year after his Tour-level main draw debut as a local wildcard at the ATP 500 tournament in Rio de Janeiro. At that time, he was ranked 655th and made it to the quarterfinals but the 2023 Junior US Open champion has shown tremendous growth in the last few months.
The Brazilian grabbed the title at the Next Gen ATP Finals, the event held for the Top 8 under-20 players at the end of last season in Jeddah.
He began the 2025 season by winning Canberra’s ATP Challenger Tour event. He qualified for the main draw of the Australian Open in Melbourne with three consecutive straight-set victories. On his Grand Slam main draw debut, he stunned the then World No. 9 Andrey Rublev 7-6(1), 6-3, 7-6(5).
His triumph in Buenos Aires will lift him to 68th in the ATP Rankings on Monday, making him the top-ranked Brazilian man.