ISTANBUL, TURKEY - MAY 02 : Stefanos Tsitsipas of Greece returns the ball to Damir Dzumhur (not seen) of Bosnia-Herzegovina during their TEB BNP Paribas Istanbul Open Men's tennis match at Garanti Koza Arena, in Istanbul, Turkey on May 02, 2017. (Photo by Yasin Aras/Anadolu Agency/Getty Images)
