João Fonseca, Brazil’s No. 1 and 45th in the ATP world ranking, was confirmed this Wednesday (15) for the ATP 250 in Buenos Aires, Argentina. The tournament runs from February 7 to 15, 2026, one week before the Rio Open. At 19 years old, the Rio native will defend the title won in 2025, when he became the youngest Brazilian to claim an event on the main circuit.
The confirmation comes after Fonseca fell in the first round of the ATP 250 in Brussels, Belgium, on Tuesday (14). He lost to Dutch player Botic van de Zandschulp, 86th in the world, 2 sets to 0, with scores of 7/5 and 7/6 (2), on indoor hard court. The tennis player’s next commitment is the ATP 500 in Basel, Switzerland, starting October 20.
In Buenos Aires last year, Fonseca entered as 99th in the ranking and left in the top 100 after beating four Argentines in the campaign. The final win against Francisco Cerúndolo, then 28th, by 6/4 and 7/6 (1), earned 250 points and $100,000 in prize money.
The Argentine event kicks off the 2026 South American clay swing. Fonseca, coached by Guilherme Teixeira, has 34 wins in 2025 across ATP tournaments and challengers.
João Fonseca está confirmado no ATP 250 de Buenos Aires!
— João Fonseca Updates (@fonsecaupdates) October 15, 2025
Ele defenderá o título que conquistou este ano 🏆 https://t.co/yvl1cqJzcw
Strong opponents on Argentine clay
Francisco Cerúndolo, 21st in the ranking and 2025 runner-up, seeks revenge against Fonseca on the courts of the Buenos Aires Lawn Tennis Club. The Argentine lost the final to the Brazilian in straight sets and now leads locally.
Lorenzo Musetti, 7th in the world, arrives as the main attraction after a Roland Garros semifinal and Monte Carlo runner-up finish. The 23-year-old Italian has yet to win an ATP on clay, but his varied game could challenge favorites.
Matteo Berrettini, 61st, debuts in the tournament with powerful serves over 200 km/h. Recovering from injuries, the former top 10 Italian aims for points to return to the top 50 before Wimbledon.
Gael Monfils, 65th, will make his circuit farewell in 2026, with Buenos Aires as a mandatory stop. The 39-year-old Frenchman has 12 ATP titles and promises entertainment on court.
Historic campaign that shifted the ranking
Fonseca started 2025 with a title at the Canberra Challenger, without dropping a set, and climbed to 113th. In Buenos Aires, he defeated Tomás Etcheverry (6/3, 6/3), Federico Coria (2/6, 6/4, 6/2), and Mariano Navone (saving two match points in a comeback by 3 sets to 2).
In the semifinal, the Brazilian beat Laslo Djere 6/4, 4/6, 7/3 in the decisive tie-break. The final against Cerúndolo sealed the win, boosting him 31 spots in the ATP ranking.
The Rio player accumulated $1 million in career earnings up to that point, surpassing the mark with the $100,000 from the Argentine trophy. He became the 15th Brazilian with an ATP title.
- Win over Etcheverry marked the first top 50 elimination in straight sets.
- Against Navone, Fonseca saved match points in the third set, deciding in a 7/5 tie-break.
- Semifinal required three sets, with 78% first serve converted to points.
Recent performance on European indoor courts
Fonseca played 27 matches in the first three months of 2025, more than top 10 players like Zverev (20 matches). On hard courts, he has 20 wins and 6 losses, highlighted by the Australian Open where he beat Andrey Rublev (top 10) 3 sets to 0.
At the US Open, he advanced to the second round before falling to Tomas Machac (7/6, 6/2, 6/3). In the Davis Cup, he contributed two wins against Greece, securing qualifiers for 2026.
In the Laver Cup, he represented Team World and beat Flavio Cobolli. At the Phoenix Challenger, he took the title, adding 10 wins in 11 matches at that level.
The Brazilian reached the third round in the Miami Masters 1000, beating Ugo Humbert. At Wimbledon, he stopped in the third round, showing adaptation to grass with 3 wins and 3 losses.
Preparation for the South American swing
Basel offers indoor hard courts, contrasting with Buenos Aires clay. Fonseca, with 8 wins in 5 losses on clay in 2025, adjusts his game for deeper returns.
The Rio Open follows immediately, with Fonseca confirmed for the 12th edition. He debuted professionally in the tournament in 2023 and reached quarters in 2024.
Coach Teixeira emphasizes consistency in tie-breaks, where Fonseca converted 70% of decisive points in 2025. The Rio native has 44 wins and 23 losses since January 2024.
- Clay focus: Adjustments to forehand for higher topspin, reaching 181 km/h in Miami.
- Mindset: Praise from Djokovic and Kyrgios highlights resilience in long sets.
- Schedule: After Basel, break for acclimation to South American clay.
Technical evolution since initial title
Fonseca improved his serve by 15% in aces per match since Buenos Aires, reaching 12 per game on hard. His backhand cross-court gained precision, with 65% winners in short rallies.
In 2025, he competed in all Majors with at least one win: Australian Open (2nd round), Roland Garros (3rd), Wimbledon (3rd), and US Open (2nd). The world No. 42 came in September, ninth best Brazilian historically.
The 1.85m player uses height for aggressive volleys, converting 55% into points. In challengers, he won Phoenix without dropping sets, adding 500 extra points.
Against top 100, Fonseca is 21-14 in 2025, including wins over Rublev and Tsitsipas in Davis Cup. His forehand reaches speeds over 180 km/h, rivaling Berrettini.
