Sinner battles in soaring temperatures as Cerundolo forces fifth set on day five of French Open 2026

Juan Martín Cerundolo leads Jannik Sinner 3-0 in the fifth set. The world No 1, who had not lost a match in 30 outings, is on the brink of the most staggering upset of the sporting year after a physical collapse on Court Philippe‑Chatrier.

Sinner’s meltdown: from cruise control to crisis

Sinner had looked invincible. He swept through the first two sets 6‑3, 6‑2 and led 5‑1 in the third, serving for the match. Then, without warning, his body betrayed him. The Italian began to wilt in the Paris heat, losing 15 consecutive points. Serving at 5‑4 in the third set, he dropped to 0‑40 and was seen clutching his back on a hoarding. The umpire gave him a choice: call the physio or take a time violation. He opted for treatment, but the nature of his problem – injury or cramp – remained unclear.

What followed was a slow‑motion disaster. Sinner left the court for a bathroom break and a change of kit. He returned feeling dizzy and wanting to vomit but unable to do so. The question of whether he had heat stroke was raised. Under the rules, a medical timeout for cramp is not permitted, but he could be assessed. While he lay in the air‑conditioned locker room, Cerundolo sat outside in the sun under an umbrella, waiting. “It’s hard to watch really,” the commentary noted, “a consummate athlete reduced to loping about.”

Cerundolo, ranked 114th, kept his composure. He did not resort to reckless shots; he methodically moved towards the opportunity of a lifetime. He broke Sinner to love, then held to love – a rare feat against a world No 1. Sinner, still able to hit the ball but unable to run for it, managed to break back briefly to level the fourth set at 1‑1, but the effort drained him. He lost the set 7‑5, forcing a decider.

In the fifth set, Cerundolo broke Sinner through deuce to lead 1‑0. He then broke again for 3‑0 after Sinner, clearly exhausted, swatted a forehand into the net. At 15‑30 Cerundolo dashed in to flip a drop shot down the line, leaving the world No 1 spectating. The scoreboard read 3‑0 to the Argentine. “The overwhelming favourite is surely going out!” the press box reacted. “This is the biggest shock of the sporting year – and then some!”

Kouame vs Vallejo: a separate epic unfolding

On Court Suzanne‑Lenglen, a parallel drama was unfolding. Seventeen‑year‑old Kouame, who turned 17 in March, was leading 6‑3, 7‑5, 5‑3 before Vallejo, who had never played a five‑setter, fought back. Vallejo broke Kouame to take the third set 6‑3 and then broke again early in the fourth. Kouame, clearly struggling in the same oppressive heat, looked “wiped out.” The crowd, heavily behind the teenager, chanted his name as he held serve to force 5‑5 in the fifth. At one point, after burning a break point, he appeared to have “aged about a decade.” Vallejo, by contrast, grew in confidence. He broke for 4‑2 in the decider and served for the match at 5‑4, but Kouame saved himself with a brilliant return and held for 5‑5. At the time of writing, the match remained tight, with Kouame serving at deuce at 4‑5 in the fifth.

Other results and tournament context

Elsewhere, Francisco Cerundolo – Juan Martín’s older brother – levelled his match against Hugo Gaston at a set apiece on Court Suzanne‑Mathieu. Gaston had taken the first set 6‑2, but Cerundolo F hit back. The winner of that match will meet a qualifier who defeated Jan‑Lennard Struff in the second round. Struff had beaten Bublik in round one but could not capitalise on the No 9 seed’s absence from the draw.

On Court 14, Hubert Hurkacz led Frances Tiafoe 7‑6, 5‑5 in the first set; Tiafoe had earlier broken but Hurkacz broke back. In the same section, Flavio Cobolli cruised past Wu Tung‑lin 6‑4, 6‑4, 4‑3 and now awaits the winner of the Diaz Acosta vs Tien match. Diaz Acosta led Tien 7‑5, 4‑6, 6‑3, 5‑5 in the fourth. “Next for him: Cobolli. That should be a belter,” the commentary noted. Cobolli, with Daniil Medvedev already out of his eighth and Félix Auger‑Aliassime as his seeded last‑eight opponent, is eyeing a deep run.

In women’s singles, Diana Shnaider led McCartney Kessler 7‑6, 3‑1. Naomi Osaka, after a straight‑sets win in the second round, gave an on‑court interview in French, saying “Merci” to the crowd. She reached the fourth round for the first time since 2018 and spoke about the meaning of her on‑court outfits: “She feels she’s developed a community with her on‑court outfits, likes to keep people guessing.”

In doubles, the Wimbledon 2024 and Australian Open 2025 champions Harri Heliovaara and Henry Patten defeated Nuno Borges and Zhang Zhizhen 6‑3, 6‑3 to advance to the second round.

On Court 5, Zachary Svajda led Adam Walton 6‑3, 6‑3, 6‑7, 1‑1. Svajda, a young American, had lost the first set to Alexei Popyrin in the previous round before reeling off three straight. In the same eighth as Cobolli, he will feel he has a chance to make a deep run.

Meanwhile, the broader implications for the men’s draw were already being discussed. With Sinner on the verge of elimination and Carlos Alcaraz not involved, Alexander Zverev becomes the favourite – but as one observer noted: “Imagine if he still can’t land that elusive major … and imagine what Novak Djokovic is plotting! It’s amazing, it really is – just when we think we’ve seen it all, we’re reminded we know nothing.”