In Melbourne, Australia, Novak Djokovic was forced to retire from his Australian Open semifinal match against Alexander Zverev after losing the first set due to an injury.

Djokovic lost the opener 7-6 (5) in a tiebreaker and immediately walked around the net to concede the match to Zverev.

Fans booed as Djokovic walked off toward the locker room, and he responded by giving two thumbs-up.

Djokovic aimed for an 11th Australian Open title and a record 25th Grand Slam overall, but sustained a left leg injury during his quarterfinal win over Carlos Alcaraz.

With this, the second-seeded Zverev advances to his first final at Melbourne Park and is set to compete against the winner of the semifinal match between the defending champion, No. 1 Jannik Sinner of Italy, and No. 21 Ben Shelton from the United States.

Zverev is a two-time runner-up at other major tournaments.

The men’s final is Sunday. In Saturday’s women’s final, No. 1 Aryna Sabalenka of Belarus will try to become the first woman since 1999 with three consecutive Australian Open titles when she faces Madison Keys of the United States.