RIO DE JANEIRO – Ignacio Buse of Peru delivered a significant upset at the Rio Open presented by Claro on Friday, defeating third-seeded Brazilian João Fonseca in a thrilling three-set match. Buse prevailed 5-7, 6-3, 6-4, securing his place in the quarterfinals of the ATP 500 tournament.
The match, delayed by two and a half hours due to rain, proved to be a tense affair. Fonseca, fueled by the energy of the home crowd at the Jockey Club Brasileiro, initially seized control, taking the first set 7-5. However, Buse demonstrated remarkable resilience, battling back to level the match and ultimately secure the victory after two hours and 13 minutes of play.
The turning point came in the third set, where Buse managed a crucial break to lead 2-1. His mental fortitude was particularly evident while serving at 5-3, facing three break points at 0-40. Amidst a vocal atmosphere, Buse reeled off five consecutive points to hold serve and close out the match. This display of composure under pressure highlighted a maturity beyond his 21 years.
Fonseca’s performance showed signs of fatigue in the later stages of the match, leading to a series of unforced errors. He was unable to convert any break opportunities against Buse in the deciding set, ultimately succumbing to the Peruvian’s consistent play. The defeat ends Fonseca’s run in the singles competition and dashes his hopes of becoming the first Brazilian champion at the Rio Open.
Buse’s victory marks the most significant win of his burgeoning career. Having broken into the world’s top 100 on January 5, 2026, the world No. 91 is steadily climbing the ranks. A former world No. 9 junior, Buse trains in Barcelona under the guidance of 2002 Roland-Garros champion Albert Costa.
The win sets up a quarterfinal clash for Buse against the winner of the match between Italy’s Matteo Berrettini and Serbia’s Dušan Lajović. Berrettini advanced to the quarterfinal after a hard-fought victory over Lajović, winning 2 sets to 1.
Despite the singles defeat, Fonseca’s participation in the Rio Open continues in the doubles competition. He is partnering with Marcelo Melo, and the pair will compete in the semi-final against Germans Jakob Schnaitter and Mark Wallner, who eliminated Brazilians Gustavo Heide and Luís Miguel.
This tournament marks Fonseca’s third of the year, following a first-round exit at the Australian Open in January and a defeat at the ATP 250 in Buenos Aires earlier this month, where he lost to Alejandro Tabilo. The Rio Open represented a significant opportunity for the young Brazilian to make a statement on home soil, but Buse proved to be a formidable opponent.
Buse’s ability to silence the partisan crowd and maintain his focus throughout the match was a key factor in his success. His composure, particularly when facing break points in the crucial third set, demonstrated a level of mental toughness that will serve him well as he continues his ascent in the professional tennis world. The victory is a testament to his dedication and the quality of his training, and positions him as a player to watch in the coming months.
The result underscores the unpredictable nature of professional tennis, where even highly-ranked players can be vulnerable to determined opponents. Buse’s triumph over Fonseca is a reminder that momentum and mental strength can often outweigh rankings and expectations, especially in the electric atmosphere of a home tournament.
