US Open: Djokovic's title defence ends, retires from Wawrinka clash

World number one Novak Djokovic saw his US Open defence end as he retired in the third set against Stan Wawrinka.

Novak Djokovic could not continue his title defense at the US Open owing to persistent trouble in his left shoulder.

Novak Djokovic is out of the US Open after retiring from his fourth-round match with Stan Wawrinka.

The Serbian battled a shoulder injury in his second-round win over Juan Ignacio Londero but appeared to suggest his condition had improved after a third-round defeat of Denis Kudla.

However, the world number one was second best throughout against the 2016 champion and called it quits after he dropped his serve to give Wawrinka a 6-4, 7-5, 2-1 lead in the third.

Wawrinka, who is in pursuit of his fourth major title, will play Daniil Medvedev for a place in the semifinals.