
Greece's Stefanos Tsitsipas returns the ball to Serbia's Novak Djokovic during their ATP Madrid Open final tennis match at the Caja Magica in Madrid on May 12, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Greece's Stefanos Tsitsipas returns the ball to Serbia's Novak Djokovic during their ATP Madrid Open final tennis match at the Caja Magica in Madrid on May 12, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)