Bettor’s $55K French Open confidence in Jannik Sinner ends in brutal betting collapse at Roland Garros shock

Jannik Sinner arrived at Roland Garros this year carrying every advantage a tennis player could ask for. The world No. 1 had won 30 straight matches, Carlos Alcaraz was out injured, and a career Grand Slam was within reach on Parisian clay. None of it mattered. World No. 56 Juan Manuel Cerundolo beat Sinner 3-6, 2-6, 7-5, 6-1, 6-1 on Thursday, completing one of the most dramatic reversals in Roland Garros history, and taking at least one gambler's entire year of profits down with him. With Carlos Alcaraz withdrawing from the tournament due to a lingering wrist issue, the draw suddenly opened up for Jannik Sinner, who arrived in Paris as a dominant -900 favorite. His early momentum looked untouched after a straight-sets win over Clement Tabur, extending a winning run that had already reached 30 matches. For a moment, it felt routine for the Italian to move deeper into the draw. That perception shifted quickly when he faced Juan Manuel Cerundolo, who refused to fold under pressure in a match that exposed Sinner’s physical strain in the Paris heat. Conditions in Paris added to the upset, with heat a factor as the match wore on. What began as control from Sinner faded, opening a window for Cerundolo to push deeper into rallies and force errors that rarely appeared early.Betting markets told a very different story as the match slipped away. One bettor, using the handle @FoaznPoker, shared that they had placed what they believed were safe returns on Jannik Sinner’s progression. They referred to the positions as "guaranteed" wagers he made on DraftKings (to the tune of $5,000) and Kalshi ($50,000) in the hopes of waking up around $1,000 richer. Another punter faced an even larger hit on Betfair, staking €31,430 (around $36,600) to secure a small return after Sinner looked in control early in the match. The momentum swing against Juan Manuel Cerundolo flipped the expectation completely, leaving the wager wiped out. The bettor later noted that the loss erased gains made across the year, though they appeared to take the outcome with unexpected humor despite the scale of the setback during the match in Paris.Beyond the numbers, the incident highlighted how quickly momentum shifts in tennis can ripple into betting markets. A match that looked settled after two sets turned into a reminder that form, conditions, and pressure can overturn expectations in minutes. For Sinner, the defeat delays another shot at history on clay, while for bettors it became an expensive lesson in how fragile “safe” predictions can be in sport.