Alexander Zverev into Aussie Open final as Novak Djokovic retires

(Photo credit: Mike Frey-Imagn Images)
Alexander Zverev qualified for his first Australian Open final when Novak Djokovic retired after the first set of their semifinal match in Melbourne on Friday.

Djokovic, 37, was clearly struggling with a left leg injury throughout the first set, which went to a tiebreaker. When the Serbian put avolley into the net to lose the tiebreak 7-5 and the first set after 1:21, he immediately