Austria's Dominic Thiem celebrates after beating Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Austria's Dominic Thiem reacts as he plays against Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Austria's Dominic Thiem returns the ball to Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Austria's Dominic Thiem returns the ball to Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Austria's Dominic Thiem returns the ball to Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Austria's Dominic Thiem plays against Switzerland's Roger Federer during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Switzerland's Roger Federer returns the ball to Austria's Dominic Thiem during their ATP Madrid Open quarter-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)

Switzerland's Belinda Bencic wipes herself with a towel as she leaves the court after been defeated by Romania's Simona Halep during their WTA Madrid Open semi-final tennis match at the Caja Magica in Madrid on May 10, 2019. (Photo by GABRIEL BOUYS / AFP via Getty Images)