Netherlands' Kiki Bertens celebrates on the podium after winning the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates on the podium after winning the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates on the podium after winning the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates in the podium after winning the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates in the podium after winning the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by JAVIER SORIANO / AFP via Getty Images)

Romania's Simona Halep celebrates her second place after the WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by OSCAR DEL POZO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates after defeating Romania's Simona Halep during their WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by OSCAR DEL POZO / AFP via Getty Images)

Netherlands' Kiki Bertens celebrates after defeating Romania's Simona Halep during their WTA Madrid Open final tennis match at the Caja Magica in Madrid on May 11, 2019. (Photo by OSCAR DEL POZO / AFP via Getty Images)