Stefanos Tsitsipas shocked the world tennis as he defended champion Roger Federer in the Australian Open fourth round. Stefanos beat Federer, who is 17 years his senior, 6-7 (11-13), 7-6 (7/3), 7-5, 7-6 (7/5) on Rod Laver Arena. “There’s nothing really I can say to describe this, I’m the happiest man on earth right now.” […]