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,

Novak Djokovic’s quest for a record 25th grand slam title has been cut short at the Australian Open after he stunningly retired from his semifinal match due to a left leg injury.

When it comes to effort on the tennis court, few players can compare to the legendary Jimmy Connors. The eight-time Grand Slam champion built a reputation for being one of the most hard-working players on the ATP Tour.

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.

Facing Sinner reminded Alexander Zverev of trying to solve the challenge presented by the 24-time major champion Djokovic.