Alexander Zverev into Australian Open final as Djokovic retires - ESPN

MELBOURNE, Australia — Twenty-four-time Grand Slam champion Novak Djokovic retired from his Australian Open semifinal match against Alexander Zverev on Friday afternoon, unable to continue due to a muscle tear in his left leg.

After Zverev had secured a marathon 81-minute first set in a tiebreak, Djokovic, who was playing with heavy strapping on his left thigh, walked gingerly to the net and shook hands with the world No. 2, conceding the match and confirming Zverev's place in Sunday's final.

The capacity Rod Laver Arena crowd booed Djokovic as he headed for the exit, and he responded by flashing two thumbs up.

«I did everything I possibly can to manage the muscle tear that I had,» a dejected Djokovic told reporters minutes after stepping off the court. «Medications and the strap and the physio work helped to some extent today, [but] towards the end of that first set I just started feeling more and more pain. It was getting worse and worse. It was just too much to handle for me at the moment.

»I knew even if I won the first set it was going to be a huge uphill battle for me to stay physically fit enough to stay with him in the rallies for another, god knows, two, three, four hours. I don't think I had that, unfortunately, today in the tank. Unfortunate ending, but I tried."

Zverev, who will play in his first Australian Open final against either defending champion Jannik Sinner or No. 21 Ben Shelton, addressed the booing fans and defended Djokovic in his on-court interview.

«The very first thing I want to say is, please, guys, don't boo a player when he goes out with injury,» Zverev said. «I know that everybody paid for tickets and wants to see hopefully a five-set match. He has won this tournament with an abdominal tear,