Ignacio Buse’s Upset Victory Over Joao Fonseca at the Rio Open

Rio de Janeiro – Ignacio Buse of Peru delivered a significant upset at the Rio Open presented by Claro on Thursday, February 20, 2026, defeating home favorite Joao Fonseca 5-7, 6-3, 6-4 in the second round. The match, lasting two hours and 26 minutes, marked Buse’s first appearance in an ATP 500 quarter-final since the series began in 2009.

A Hard-Fought Battle

Despite dropping the first set, Buse capitalized on Fonseca’s 43 unforced errors to secure the victory. The Peruvian saved eight of the nine break points he faced, including crucial saves at 3-4 in the third set, demonstrating composure under pressure according to Infosys ATP Stats.

Buse Reflects on the Match and His Journey

“Today was a really difficult match,” Buse said after the win. “We all know the potential that Joao has. We are really close friends. So that was also hard today.” Buse has experienced a rapid rise in the PIF ATP Rankings, climbing from No. 230 one year ago to a career-high No. 91.

“I tried to deal with the pressure the best that I can,” Buse added. “I did it well today. And next time if I do it bad, I will learn and try to do it better.”

Fonseca Disappointed with Performance

Joao Fonseca expressed his disappointment following the loss, citing unforced errors as a key factor. Ubitennis reports Fonseca stated, “At this level, you can’t miss opportunities like that. It was silly of me, I got a little flustered at times, but it’s a process, keep improving, keep working.”

Fonseca’s start to 2026 has been challenging, with a withdrawal from the Brisbane tournament due to injury and first-round losses at the Australian Open and Buenos Aires Open. His win against compatriot Thiago Monteiro in the first round of the Rio Open was his first Tour-level win of the year as reported by the Rio Open.

Looking Ahead

Ignacio Buse will now face Matteo Berrettini in the quarter-finals, after Berrettini defeated Dusan Lajovic 3-6, 6-4, 6-2. Buse’s victory marks a significant milestone in his career and his performance in Rio is attracting attention on the ATP Tour.