Novak Djokovic is out of the Australian Open in stunning fashion. The 24-time slam champion medically retired immediately after dropping the first set of his semifinal match against No. 2 Alexander Zverev in a tiebreak 7-6 (5).

Novak Djokovic has retired from his Australian Open semifinal against Alexander Zverev after losing the first set in a tiebreak. Djokovic missed a regulation putaway volley on top of the net down 5-6,

Zverev will face defending Australian Open champion and No. 1 seed Jannik Sinner, who beat American Ben Shelton 7-6 (2), 6-2, 6-2, in Sunday's final. Zverev is pursuing his first major tournament title.