On Thursday, May 28, world No. 1 Jannik Sinner faced world No. 56 Juan Manuel Cerundolo in a Round of 64 match in the 2026 French Open in Roland Garros. The match began at noon local time, taking stage on the historic Court Philippe Chatrier in Paris, France. Details like time and location often mean very little to the casual tennis fan. The world No. 1 should be able to beat the 56th-ranked player anywhere, right? Well, nothing about Day 5 at Roland Garros — and this match especially — was normal. Cerundolo ended up pulling off one of the biggest upsets in tennis history, winning 3-6, 2-6, 7-5, 6-1, 6-1. That upset snapped Sinner’s 30-match winning streak, and it also put his pursuit of the Career Grand Slam on hold.
How did Juan Manuel Cerundolo upset Jannik Sinner?
Surely, many people woke up and saw that Sinner lost. And for most tennis fans, the quick assumption was probably that Cerundolo played the match of his life and Sinner showed up with nothing to offer. That couldn’t be further from the truth. Sinner was actually serving for the match at 6-3, 6-2, 5-1, looking like he was ready to put a bow on a fantastic performance. From there, things spiraled out of control.
Sinner denied that he was dealing with heat stroke and cramping, but that’s exactly what did the Italian in. Perhaps he was ill and feeling less than 100% heading into the match, and fatigue might have been a factor with Sinner having been unbeatable during the European clay-court season. Being unbeatable means playing a ton of matches, so that isn’t crazy. But the temperature on Thursday got above 90 degrees, and it was actually the hottest May day in Roland Garros history. That was the main issue.
Sinner has always struggled to play in grueling daytime conditions, which is something I noted when doing the Beating The Book podcast with Gill Alexander and Drew Dinsick. We discussed the Italian’s pre-tournament price to win the event, and I felt there was no value in grabbing him at roughly -300 odds. Sinner was undoubtedly the best player in the field, but it was clear the conditions were going to be a problem. That didn’t mean Sinner would 100% succumb to the heat, but that is exactly what ended up happening.
Sinner rapidly lost his ability to move himself around the court, the pop on his serve and baseline strokes vanished, and he simply went into survival mode as he baked in the sun.
All Cerundolo needed to do from Set 3 to the end of Set 5 was put the ball in play, avoid mistakes, and make Sinner move. More often than not, the Italian didn’t even bother to move his legs. He was shaking, he was complaining about dizziness and nausea, and he was looking for answers anywhere he could find them. Unfortunately, there were none.
If Cerundolo deserves credit for anything, it’s maintaining his focus and not giving Sinner any momentum towards the start of the fifth set. Sinner used the second half of the fourth set to rest and make sure he had something in the tank for the decider. In the past we have seen the Italian use similar strategies to work through his on-court physical struggles. It worked for him against Eliot Spizzirri at the Australian Open. And just a few days ago, Casper Ruud won a five-set match against Roman Safiullin in similar fashion. However, this match started too early in the day. It was only getting hotter and hotter, and Sinner never found his legs again.
A pretty good argument can be made that any ATP-level player, and probably most Challenger-level players, would have beaten Sinner in this one. But in the end it was Cerundolo that did it, and the Argentinean clearly knew how fortunate he was. Cerundolo barely celebrated the win, and he made a telling comment after the match.
“I got lucky. I don’t even want to say that I beat him,” said Cerundolo.
This wasn’t a match that was choked away. It wasn’t a collapse either. It just kind of was what it was. Sinner’s team needs to search for new ways for him to beat the heat. Until then, any time he plays during the day, his body will be at risk of failing if it’s hot enough outside. However, if there’s any fault within the Sinner camp, it was making the decision to play at noon.
Tournament organizers are often very kind to the best players in the world, which is why no male No. 1 had ever played the opener on Chatrier. Well, playing at noon was a decision from Team Sinner. He had options heading into the day, including playing an hour earlier on Court Suzanne Lenglen. Had he done that, he would have closed out the match against Cerundolo and been drinking Lavazza a half hour before the heat really started to kick in. In retrospect, the way all of that played out was extremely puzzling.
How big of an upset was this?
According to Sportico, since 2000, only Rafael Nadal has entered a major as a bigger favorite than Sinner was here. Oddly enough, Nadal lost that year. He was -400 entering that event, but he fell to Robin Soderling in the fourth round of this very tournament — which the Spaniard was normally able to win in his sleep. Sinner was about -300 heading into this one. The Italian was on fire in the weeks leading up to this tournament, plus Carlos Alcaraz, who had won two consecutive Roland Garros titles and is Sinner’s biggest rival, isn’t in the field. We even saw some other talented players drop out, including Lorenzo Musetti and Arthur Fils.
Sinner was just widely expected to win this tournament. Tennis Abstract actually had him at 75.1% to complete the Career Grand Slam next Sunday. Clearly that wasn’t meant to be.
As far as this specific match goes, this might be the biggest upset in tennis history. Sinner was a -50000 favorite at DraftKings Sportsbook. Meanwhile, you could have gotten 30-1 odds on Cerundolo at FanDuel Sportsbook. You simply don’t see these types of favorites lose like this. Soderling over Nadal was stunning, but the Spaniard wasn’t favored as heavily in the betting market.
What happens next?
From here, Cerundolo heads into a meeting with Martin Landaluce. The Argentinean is favored to win that match, but his run can end at any stage now. This isn’t the type of player you should expect to see deep in this event.
For Sinner, expect a nice little vacation. The Italian said he needs some time off before he starts preparing for Wimbledon, where he’ll once again enter the tournament as a massive favorite — while also having to deal with the added pressure of being the defending champion.
For everyone else, things are about to be very interesting. Novak Djokovic is the only remaining Grand Slam champion in the draw, and the 39-year-old is surely viewing this as a golden opportunity to win major No. 25. Alexander Zverev, the new betting favorite at +185 at DraftKings, must also be pretty damn excited. Zverev is arguably the best player in tennis history to not win a major, and the draw has opened up for him completely. Some other players to watch out for are Casper Ruud and Rafael Jodar. Ruud is a two-time French Open runner-up, and he was the runner-up in Rome a couple of weeks ago. He’s one of the better clay-court players in the world, and he’ll be tough to beat moving forward. Meanwhile, Jodar is one of the sport’s rising stars, and he has already proven himself on the dirt. Perhaps he can make a special run over the next 10 days.
Overall, the men’s side of this tournament has become a land of opportunity. It’ll be fun seeing how it all ends.
