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 youngster Stefanos Tsitsipas will contest the other semi-final on Thursday.
More to follow.