Jannik Sinner’s dream of completing a Career Grand Slam suffered a heartbreaking setback at Roland Garros as the World No. 1 crashed out in the second round of the French Open 2026 after a dramatic five-set defeat against Argentina’s Juan Manuel Cerundolo. What initially looked like a routine victory for the Italian eventually turned into one of the biggest upsets in recent French Open history, with extreme Paris heat and physical discomfort completely changing the course of the match. The 24-year-old Italian arrived in Paris carrying enormous expectations. With four Grand Slam titles already in his cabinet — including two Australian Opens, a Wimbledon crown and a US Open title — the French Open remained the only missing piece in Sinner’s collection. The absence of defending champion Carlos Alcaraz had only increased hopes among fans and experts that this could finally be Sinner’s year on clay.
For nearly two sets and a half, those expectations appeared fully justified. Facing World No. 56 Juan Manuel Cerundolo, Sinner looked untouchable early on. His movement was sharp, his baseline hitting was precise and his trademark aggression left the Argentine struggling to survive the rallies. Sinner wrapped up the opening set 6-3 in just 36 minutes before cruising through the second set 6-2. Even in the third set, he looked firmly in control after breaking serve twice to move ahead 5-2.
At that stage, the match seemed over. The crowd inside Court Philippe-Chatrier was already preparing for another straightforward Sinner victory and a place in the third round. Then everything changed. Under the scorching Paris heat, with temperatures reportedly touching 33 degrees Celsius, Sinner suddenly began to show signs of physical distress. After several long rallies, he repeatedly stood bent over with his hands on his waist. His movement became noticeably slower and his intensity dropped sharply. The Italian eventually requested a medical timeout midway through the third set, prompting concern among spectators and commentators alike.
Although he returned to court after treatment, he was no longer the same player. Cerundolo immediately sensed the shift in momentum. The Argentine, who had spent most of the match defending desperately, suddenly found renewed belief. He began extending rallies, forcing Sinner to cover more ground and making the Italian play one extra shot every point. The pressure gradually mounted as Sinner struggled physically and mentally to regain control. From 5-2 down in the third set, Cerundolo produced a remarkable comeback to steal the set 7-5. That comeback completely transformed the atmosphere of the match. The confidence that had carried Sinner through the opening stages disappeared, while Cerundolo began playing with increasing freedom and aggression.
The final two sets turned into a nightmare for the World No. 1. Clearly hampered by exhaustion and discomfort, Sinner could no longer maintain his usual intensity from the baseline. His footwork slowed dramatically, unforced errors increased and his serve lost much of its penetration. Cerundolo capitalised brilliantly, dominating long exchanges and forcing Sinner into uncomfortable positions repeatedly.
The Argentine stormed through the fourth and fifth sets 6-1, 6-1 to complete an extraordinary comeback victory: 3-6, 2-6, 7-5, 6-1, 6-1. As the final point ended, Sinner walked off court looking devastated. The defeat was not just another upset loss; it represented a painful collapse of what many believed could have been his strongest opportunity yet to conquer Roland Garros and complete the Career Grand Slam.
For Cerundolo, meanwhile, the victory was undoubtedly the greatest moment of his career. Defeating the World No. 1 on one of tennis’ biggest stages instantly elevated the Argentine into the global spotlight. His resilience after losing the first two sets demonstrated tremendous mental strength, especially against a player widely regarded as one of the most complete competitors in modern tennis. The result also leaves the men’s draw wide open. With Sinner eliminated and Alcaraz absent, attention now shifts heavily toward second seed Alexander Zverev, who continued his campaign with a comfortable straight-set victory over Tomas Machac. The German looked in complete control throughout his second-round match, winning 6-4, 6-2, 6-2 to book his place in the third round.
Zverev, who has consistently performed well at Roland Garros over recent years, now finds himself among the strongest favourites for the title. His powerful serve and ability to thrive in long clay-court rallies could make him extremely dangerous as the tournament progresses. In the women’s singles draw, sixth seed Amanda Anisimova and former finalist Karolina Muchova also advanced comfortably. Muchova defeated Kamilla Rakhimova in straight sets, while Anisimova benefited after her opponent Julia Grabher retired due to injury. Yet despite several major results elsewhere, the day belonged entirely to Cerundolo and the dramatic collapse of Sinner’s title ambitions.
The Italian’s defeat also raises important questions about the physical demands of modern tennis, especially during extreme weather conditions. Over the last few years, several players have struggled in Grand Slam events because of intense heat, with organisers increasingly facing criticism regarding scheduling and player welfare.While Sinner’s fighting spirit remained admirable, he refused to retire despite obvious discomfort — the match highlighted how quickly physical issues can change outcomes at the highest level of the sport. One moment he was cruising toward victory; the next he looked physically helpless against an opponent growing stronger with every game.
Former players and analysts were quick to praise Sinner’s determination despite the defeat. Many pointed out that his willingness to continue battling, even when clearly struggling physically, reflected the mentality that has already made him a multiple Grand Slam champion. However, they also stressed the importance of recovery and long-term fitness management ahead of the rest of the season. For Sinner himself, the disappointment will undoubtedly hurt deeply. The French Open has long been considered the most difficult major for him to win because of the physical demands of clay-court tennis. This year appeared to present the ideal opportunity, particularly with several rivals either absent or struggling for form.
Instead, Paris once again proved cruel. Still, at only 24 years of age, Sinner’s story at Roland Garros is far from over. His overall development over the last few seasons has shown remarkable maturity, and he remains one of the defining players of his generation. Defeats like this can often become defining moments that shape future champions. For now, though, the image that will remain from this year’s French Open is that of a physically drained World No. 1 walking slowly off the Paris clay, while an inspired underdog celebrated one of the greatest victories of his career under the blazing French sun.
