Jannik Sinner's Shanghai Masters title defence came to a cruel end on Sunday after he was forced to retire during the deciding set of his third-round clash with Tallon Griekspoor. 

Griekspoor led Sinner 6-7 (7-3) 7-5 3-2 before the second seed appeared to be struggling with cramp in his right thigh, and was ultimately unable to continue the rest of the match. 

The pair traded blows in the opening set, with Sinner able to get the better of Griekspoor in the tie-break, eventually sealing the early advantage at the third time of asking. 

Sinner had the opportunity to force an early break in the second but squandered three opportunities to do so, with Griekspoor holding on to ensure he kept pace with the Italian. 

And the world number 31 ensured the encounter would go the distance with a timely break to love in the 11th game, before levelling the contest on serve shortly after. 

The pattern of the match continued in the decider until Sinner went 2-1 down. At the changeover, he didn't sit and instead put his legs up on his bench to try and ward off cramp.

However, it proved in vain, with Sinner bowing out to hand Griekspoor the win, with the Dutchman taking on Valentin Vacherot next in China. 

"This is definitely not the way you want to win," said Griekspoor. "Brutal conditions here in Shanghai all week already.

"We were a bit lucky to play in the evening without sun, but two hours and 36 minutes on the clock, middle of the third set. I'm sorry for him, I wish him a speedy recovery."

Griekspoor advances 6-7(3), 7-5, *3-2 as Sinner is forced to retire during the third set in Shanghai...@SH_RolexMasters | #RolexShanghaiMasters pic.twitter.com/ikJUzmts3X

— ATP Tour (@atptour) October 5, 2025

Data Debrief: Sinner suffers similar fate

Having won the final of the China Open earlier this week, Sinner arrived in Shanghai as the overwhelming favourite for the title, but a similar scenario played out here to stop his hopes of reclaiming his crown. 

Indeed, having retired in the Cincinnati Open final against Carlos Alcaraz, Sinner is now the first player to lose via retirement as defending champion at multiple and consecutive ATP Masters 1000 events since the format's introduction in 1990.

Griekspoor, meanwhile, has become the first Dutchman to reach the fourth round at the Shanghai tournament.