This week, the Herald is reporting on the ground from the Argentina Open, so check back for updates!

Updated Saturday at 5 p.m.

The skies were stormy above the Guillermo Vilas central court on day five of the 2025 Argentina Open. 

The night shift delivered great tennis as top-ranked Argentine Francisco Cerúndolo (28 ATP singles ranked) shocked world number two Alexander Zverev, from Germany, 3-6, 6-3, 6-2. He thus became the first Argentine tennis player to defeat a top-two player since Diego Schwartzman beat Rafael Nadal at the 2020 Rome Masters 1000.

The first set started as a very hard-fought affair. The court, slowed down due to rains in the day shift, hindered Zverev’s fast-paced game. However, a couple of double faults at 3-2 cost Cerúndolo, who handed the German an advantage he’d manage to cling to in order to wrap up the set.

Another couple of double faults by the Argentine player helped Zverev to a 2-1 early lead in the second. Fans, however, did their part, cheering Cerúndolo on to make a comeback. He managed to claim back the break of serve, win his own, break again, and then hold the advantage, winning four games in a row. After a short rain delay, he tied the match, serving out the set.

In the third set, it was Cerúndolo who took an early advantage, with Zverev growing more and more dissatisfied with the Argentine crowd. After going up 3-1, the Argentine managed to break his opponent’s serve one more time and win his own to build a 5-1 lead. Cerundolo wrapped up the game 6-2 to secure what he called “the biggest win of his career.”

After the match, Zverev wasn’t too shy about his feelings towards the Argentine crowd.

“I loved [playing in Buenos Aires],” he told the ATP press person. “The only problem is the public, who doesn’t know how to behave during a tennis match. That’s a bit sad because the organization is brilliant, the tournament is excellent and the people who work here are incredible, but the public makes it very difficult for you if you are not an Argentine.”

Cerúndolo defended the fans, arguing that the pressure from the stands is felt everywhere.

“When you play against a local, in France, Brazil, everywhere, fans will always support them, and they will want to take you out of the game,” he said.

Cerúndolo will now go up against Spain’s Pedro Martínez, who benefited from Italian Lorenzo Musetti’s retirement from the tournament due to a leg injury, for a place in the final.

The star of the day shift was Brazilian up-and-comer João Fonseca (99), who beat Argentina’s Mariano Navone (47) 3-6 6-4, 7-5

The 18-year-old from Rio de Janeiro was looking to reach his first ATP Tour semifinals and get back at Navone, who denied him that chance at the 2024 Rio de Janeiro quarterfinals.

With Brazilian fans out in full force, the game soon resembled the Davis Cup as each player’s fans tried to out-cheer their rivals.

Early on, it looked like the path was clear for Navone. His smart defense forced Fonseca into erratic shot selection, rendering him unable to push the Argentine like he did with Coria and Etcheverry earlier in the tournament. He gave away two breaks of serve at 2-1 and 4-1, helping the Argentine to a clear lead. However, Navone failed to wrap it up with his serve at 5-1 and had to defend three break points before closing the set on his terms.

The second set started as a much closer affair, but the rain quickly became the main protagonist. Navone managed to break the Brazilian youngster’s star and take the lead after a short delay at 2-2, but then the rain came back hard. 

Navone and Fonseca went on to break each other’s serve three times in a row. The Brazilian finally held for 5-4, and went on to break the Argentine’s serve once again to wrap up the second set.

It looked like things were back on track for Navone in the third set. He broke Fonseca’s serve in the first game, and held that advantage until 5-3, where he had two match points on the Brazilian’s serve. However, the 18-year-old recovered, breaking Navone’s serve to make it 5-5. The mood swung: Fonseca won his serve and put the Argentine on the defensive in his next serving turn. Despite saving a matchpoint at 30-40, Navone couldn’t repeat the feat two points later and became the third Argentine in a row to fall to Fonseca.

He’ll face Serbian Laslo Djere (112 ATP singles ranked), who beat Brazil’s Thiago Seyboth Wild (77) by 7-6 6-3 in the first match of the day. Djere, who’s yet to have his serve broken in the tournament, reached his 20th ATP Tour semifinal and will return to the top 100 for the first time since August.

Cover photo: Francisco Cerúndolo. Credit: Argentina Open 2025