Stefanos Tsitsipas from Greece returns a ball to David Goffin from Belgium during their Millennium Estoril Open ATP 250 Singles half-final tennis match, in Estoril, near Lisbon, on May 4, 2019. (Photo by Carlos Palma/NurPhoto via Getty Images)
Stefanos Tsitsipas from Greece returns a ball to David Goffin from Belgium during their Millennium Estoril Open ATP 250 Singles half-final tennis match, in Estoril, near Lisbon, on May 4, 2019. (Photo by Carlos Palma/NurPhoto via Getty Images)