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.”
After beating Russia’s Daniil Medvedev in a gruelling last-16 match on Monday, Djokovic said he had a back injury which he “hoped” to manage before facing Nishikori.
Any fears the 14-time Grand Slam champion may be hampered were quickly allayed.
Once he broke in the second game for a 2-0 lead, plus again in a sixth game where Nishikori coughed up two double faults for 5-1, it never looked like he would lose on Rod Laver Arena.
Nishikori had spent almost 14 hours on court in his four matches up to the quarters, over four hours more than the Serb.
And it showed as the Japanese player’s hopes was ruined by injury.
He called a medical time-out at the end of a first set which he lost in 31 minutes, requiring treatment from a physio on his right quad before returning to the court with heavy strapping.
Nishikori lasted another five games, losing serve in two, but was clearly struggling and decided he could not carry on with less than an hour on the clock.
“This is what the doctor ordered for after two nights ago, not to spend too much time on the court,” Djokovic joked.
