Alexander Zverev frames a forehand into the stands to end an epic Novak Djokovic service game.

With Alexander Zverev all over the net, Novak Djokovic hits a pinpoint lob to win a crucial point in the first set tiebreak.

MELBOURNE, Australia (AP) — An injured Novak Djokovic quit after dropping the first set of his Australian Open semifinal against Alexander Zverev on...

Novak Djokovic retired injured after losing the opening set of his clash with Alexander Zverev on Friday, sending the German to a first Australian...

Alexander Zverev tells the crowd not to jeer Novak Djokovic in a sporting gesture after the Serbian quit the match.

Alexander Zverev tells the crowd not to jeer Novak Djokovic in a sporting gesture after the Serbian quit the match.

MELBOURNE,  (Reuters) – Novak Djokovic retired injured after losing the opening set of his clash with Alexander Zverev yesterday, sending the...

MELBOURNE,  (Reuters) – Novak Djokovic retired injured after losing the opening set of his clash with Alexander Zverev yesterday, sending the...

MELBOURNE, Australia (AP) — An injured Novak Djokovic quit because of a torn muscle in his left leg after dropping the first set of his Australian...

MELBOURNE, Australia (AP) — An injured Novak Djokovic quit because of a torn muscle in his left leg after dropping the first set of his Australian...