Defending champion Jannik Sinner retired Sunday from the Shanghai Masters after suffering a leg injury in his third-round match against the Netherlands' Tallon Griekspoor.
The world number two began to experience issues in the fourth game of the third set, and tried to persevere before abandoning the match when trailing 6-7 (3/7), 7-5, 3-2.
After an evenly matched first set, the four-time Grand Slam winner showed his teeth in the tiebreak, hitting two aces to take an early lead.
In the second set the tension picked up, with the Dutchman surviving three break points in the second game.
But it was Griekspoor who broke in the 11th game with a backhand, pushing the match into post-midnight territory.
Sinner ended the fourth game of the third set crouched over in pain, limping around the court.
His condition did not improve in the fifth and he hit the ball into the net multiple times, providing an easy break for his opponent, before having to be helped to his chair at the end of the game and then calling it quits.