Sports Rafael Nadal schools 20-year-old Stefanos Tsitsipas in Australian Open semifinals January 24, 2019January 24, 2019Sandra Harwitt, Special to USA TODAY SportsComments Off on Rafael Nadal schools 20-year-old Stefanos Tsitsipas in Australian Open semifinals Rafael Nadal, 32, showed 20-year-old Stefanos Tsitsipas why he is a 17-time Grand Slam champion, making it look easy in Australian Open semifinals.