ISTANBUL, TURKEY - APRIL 24 : Victoria Kamenskaya of Russia in action against Anna Kalinskaya (not seen) of Russia during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : Anna Kalinskaya of Russia in action against Victoria Kamenskaya (not seen) of Russia during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24: Basak Eraydin of Turkey in action against Alla Kudryavtseva of Russia (not seen) during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25 : Tsvetana Pironkoca of Bulgaria in action against Basak Eraydin (not seen) of Turkey during the TEB BNP Paribas Istanbul Cup women's tennis match at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : Maria Sakkari of Greece in action against Danka Kovinic (not seen) of Montenegro during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : A pair of sport shoes of Andrea Petkovic of Germany is seen during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : Andrea Petkovic of Germany in action against Dayana Yastremska (not seen) of Ukraine during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : A few people watch the match between Dayana Yastremska of Ukraine and Andrea Petkovic (not seen) of Germany during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : Dayana Yastremska of Ukraine waits as she gives a break on the match against Andrea Petkovic (not seen) of Germany during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : A tennis racket of Dayana Yastremska of Ukraine is seen during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24 : Dayana Yastremska of Ukraine in action against Andrea Petkovic (not seen) of Germany during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 24: Fiona Ferro of France in action against Anastasiya Komardina of Russia (not seen) during the TEB BNP Paribas Istanbul Cup women's qualifying tennis match at Garanti Koza Arena in Istanbul, Turkey on April 24, 2017. ( Berk Özkan - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25: Alexandra Cadantu of Romania in action during the TEB BNP Paribas Istanbul Cup women's couple tennis match between Cagla Buyukakcay of Turkey - Timea Babos of Hungary against Alexandra Cadantu of Romania - Cornelia Lister of Sweden, at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25: Cornelia Lister of Sweden in action during the TEB BNP Paribas Istanbul Cup women's couple tennis match between Cagla Buyukakcay of Turkey - Timea Babos of Hungary against Alexandra Cadantu of Romania - Cornelia Lister of Sweden, at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25: Timea Babos of Hungary in action during the TEB BNP Paribas Istanbul Cup women's couple tennis match between Cagla Buyukakcay of Turkey - Timea Babos of Hungary against Alexandra Cadantu of Romania -Cornelia Lister of Sweden, at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25: Cagla Buyukakcay of Turkey in action during the TEB BNP Paribas Istanbul Cup women's couple tennis match between Cagla Buyukakcay of Turkey - Timea Babos of Hungary against Alexandra Cadantu of Romania -Cornelia Lister of Sweden, at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25: Cagla Buyukakcay of Turkey greets people after winning the TEB BNP Paribas Istanbul Cup women's couple tennis match between Cagla Buyukakcay of Turkey - Timea Babos of Hungary against Alexandra Cadantu of Romania -Cornelia Lister of Sweden, at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25 : Tsvetana Pironkoca of Bulgaria in action against Basak Eraydin (not seen) of Turkey during the TEB BNP Paribas Istanbul Cup women's tennis match at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25 : Tsvetana Pironkoca of Bulgaria in action against Basak Eraydin (not seen) of Turkey during the TEB BNP Paribas Istanbul Cup women's tennis match at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )

ISTANBUL, TURKEY - APRIL 25 : Basak Eraydin of Turkey in action against Tsvetana Pironkoca (not seen) of Bulgaria during the TEB BNP Paribas Istanbul Cup women's tennis match at Garanti Koza Arena in Istanbul, Turkey on April 25, 2017. ( İsa Terli - Anadolu Agency )