Six-time champion Novak Djokovic reached the Australian Open semi-finals after Japan’s eighth seed Kei Nishikori retired injured in their quarter-final.


Serbia’s Djokovic, 31, was leading 6-1 4-1 when Nishikori quit with a thigh problem.

Every time Djokovic has reached the last four in Melbourne he has gone on to win the tournament.

The top seed will face Lucas Pouille in Friday’s semi-final, after the Frenchman defeated Milos Raonic.

Spanish second seed Rafael Nadal and Greece’s talented 20-year-old Stefanos Tsitsipas will contest the other semi-final on Thursday.

Djokovic has not lost to Nishikori in their past 15 meetings, stretching back to the Japanese’s victory in their 2014 US Open semi-final.

“I love to battle especially against Kei, we have played so many matches in our careers,” Djokovic said.

“I hope he can recover and it is not something very serious that will take too long.

“I am sorry for everyone not having a full match tonight but thank you for showing up.”