World No. 1 Jannik Sinner lost to Juan Manuel Cerundolo at the French Open on Thursday in five sets. Sinner won the first two sets 6-3 and 6-2, led 5-1 in the third, then lost the final three sets 7-5, 1-6, 1-6 after requesting medical attention for dizziness and nausea. Sinner attributed the outcome to fatigue rather than the 32°C temperature.