Jannik Sinner’s run at the Shanghai Masters 1000 ended earlier than expected. The world's number two and defending champion was forced to withdraw in the round of 16 against Dutchman Tallon Griekspoor, 7-6, 5-7, 2-3. It was a hard contest fought in oppressive weather conditions, and the South Tyrolean succumbed to cramps after more than two hours of intense play. Not only is Sinner's withdrawal a substantial setback, but the consequences for his world ranking are also significant. With his defeat in Shanghai, the Italian loses 950 points and falls 1,340 points behind leader Carlos Alcaraz. The competition for the top slot is growing more complicated: following Vienna, it will be nearly impossible for Jannik to reclaim the top spot before the end of the year. Griekspoor, who had never beaten Sinner before (six defeats in six), won his first set against the Italian and advanced to the round of 16 against tournament surprise Valentin Vacherot. The Monegasque took advantage of Tomas Machac's retirement, which came after he lost the first set 6-0 and trailed the second 3-1.Sinner's disappointment is profound. The chances were there: six break points went unused, including decisive ones in the eighth game of the second set, when the Dutchman escaped from 0-40 at 4-3. A game that could have transformed the trajectory of the match, but instead proved to be a watershed moment. Griekspoor restored his confidence and won the set 7-5. In the third set, he watched his opponent's rapid physical collapse. The humid heat of Shanghai proved to be the greatest conceivable adversary. The South Tyrolean, clearly exhausted, tried to hold on but was forced to concede at 2-3 in the third set. A necessary defeat to avoid bigger challenges, but one that leaves a bitter taste in the mouth. Sinner had not lost a hardcourt tournament prior to the final since the 2024 Montreal Masters. A defeat that is more significant than the outcome: the emblem of a rigorous season, in which physical limitations collide with top-level ambitions. This time, Shanghai turned its back on him.