Stefanos Tsitsipas thinks big, plays bigger in win over Roger Federer

The two-time defending Australian Open champ lost in the fourth round, 6-7, 7-6, 7-5, 7-6.

What Stefanos Tsitsipas did to Roger that Federer usually does to foes

There were five things the 20-year-old did to top the 20-time major champion in Melbourne.