Six-time Australian Open champion Novak Djokovic is back in the semifinals for the first time since 2016 after an exhausted Kei Nishikori retired while trailing 6-1 4-1 in their quarterfinal clash on Wednesday night.
Nishikori had spent 13 hours and 47 minutes on court in reaching the quarterfinals, including three five-set contests and two fightbacks from two sets down, culminating in his five-hour victory over Pablo Carreno Busta on Monday night.
The No.8 seed required treatment and strapping to his right thigh after the first set, but ran out of steam at Rod Laver Arena, calling it quits after slipping a second break back in the second set with the match just 52 minutes old. It was his fifth retirement at a Grand Slam.
“I love to battle, especially against Kei,” said Djokovic, through to the 34th Grand Slam semifinal of his career.
“We’ve played so many matches throughout our careers, especially here a couple of times years ago. I hope he can recover, and it’s not something very serious.”