The world No. 6 drills the art of the dropper at his academy.
Former junior world No. 1 will wear adidas apparel and shoes.
The Serb downs Andy Murray in straight sets to join Rod Laver and Bjorn Borg on the all-time major titles list.
Stefan appears to be enjoying hiimself while watching his daddy. He'll probably be happier tomorrow when Novak comes home.
Novak Djokovic took the opening set of the Australian Open men's singles final.
The former coach of Roger Federer thinks Andy Murray needs to serve smarter to beat Novak Djokovic.
Angelique Kerber put her Australian Open trophy down so she could take a dip in the Yarra river on Sunday in Melbourne.