Tennis Bettor Loses $55K on Jannik Sinner's Shocking Upset Loss at French Open

One of the most shocking results in recent history at the French Open has cost one bettor $55K.

World No. 1 Jannik Sinner, who was a -10000 favorite at FanDuel Sportsbook in the second round of the French Open against Juan Manuel Cerundolo, was upset on Thursday morning, his first loss prior to the quarterfinals in a Grand Slam since the 2023 U.S. Open.

The result has sent a shockwave through the tennis world, and one bettor is feeling the pain after Sinner's loss. Twitter user @FoaznPoker bet $55K on Sinner to win against Cerundolo, with a chance to win about $1,000 if the World No. 1 advanced.

Instead, he's out $55K.

If you saw $999.07 on the ground, you’d pick it up, right? Jannik Sinner🔐

Couple things:
•Sinner is GUARANTEED to win
•Foazn won’t wake up at 5am to watch

I make money in my sleep; you wake up to make money #levels pic.twitter.com/SRG1Ux66iW
— Foazn (@FoaznPoker) May 28, 2026

Sinner appeared to be cramping in the extreme heat at Roland Garros, and he completely fell apart after winning the first two sets in the match, 6-3, 6-2. He was up 4-0 in the third set before the cramping appeared to set in, and eventually ended up losing the set 7-5.

World No. 1 Jannik Sinner is cramping up in 90 degree heat just as he was about to finish in straights against Cerundolo

The umpire agreed to let him call the physio

‘This is unfair for Cerundolo. This is not an injury. It’s clearly cramping,’ Jim Courier says on TC pic.twitter.com/wp6CFqLih4
— Adam Zagoria (@AdamZagoria) May 28, 2026

From there, Sinner completely unraveled, losing the fourth set 6-1 and the fifth and final set 6-1. Cerundolo, who had just two second-round appearances at a Grand Slam event in his career, is now through to the third round for the first time ever. It's an improvement on his second-round exit in last year's French Open.

The injury and/or cramping for Sinner is just a brutal way for the top player in the world to go down, especially since his rival -- Carlos Alcaraz (wrist) -- is unable to play in the French Open due to injury. It seemed that the path for Sinner to capture his first win at Roland Garros was there, but he fell well short of that.

Sinner entered the tournament at -280 to win the French Open, which translates to an implied probability of 73.68 percent. So, this is undoubtedly one of the biggest upsets in the history of the tournament.

THE BIGGEST ROLAND GARROS FAVORITE IN YEARS HAS LOST 35 OF THE LAST 50 POINTS..

This is INSANE 🤯 pic.twitter.com/r3z9LCEFKD
— br_betting (@br_betting) May 28, 2026

Betting on big favorites in tennis can be risky because of the potential for injury, and even I fell into the trap for Sinner, taking him to win this match in fewer than 26.5 games. Obviously, that didn't happen either, even though I didn't have $55K on the line.

Now that Sinner is eliminated, Novak Djokovic and Alexander Zverev have emerged as the clear favorites to win the French Open on the men's side. There are some other interesting contenders in Rafael Jodar, Casper Ruud, and American Ben Shelton (who plays his second-round match today) that also moved up in the latest odds.

For any and all bettors, this is a lesson: There is no such thing as a sure thing when it comes to sports betting.

Odds refresh periodically and are subject to change.

If you or someone you know has a gambling problem and wants help, call 1-800-GAMBLER.

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