Ukraine's Elina Svitolina hits a backhand return to Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina hits a backhand return to Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina prepares to serve to Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina makes a forehand return to Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina makes a forehand return to Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina reacts after winning a point against Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina waves as she celebrates after defeating Slovakia's Viktoria Kuzmova in their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina celebrates after defeating Slovakia's Viktoria Kuzmova in their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina waves as she celebrates after defeating Slovakia's Viktoria Kuzmova in their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina celebrates after defeating Slovakia's Viktoria Kuzmova in their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina celebrates a point win over Slovakia's Viktoria Kuzmova during their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina catches the ball as she prepares to serve to Slovakia's Viktoria Kuzmova in their second round match at the Australian Open tennis championships in Melbourne, Australia, Thursday, Jan. 17, 2019. (AP Photo/Aaron Favila)

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina serves against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina serves against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina serves against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Slovakia's Viktoria Kuzmova hits a return against Ukraine's Elina Svitolina during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Slovakia's Viktoria Kuzmova reacts after a point against Ukraine's Elina Svitolina during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Slovakia's Viktoria Kuzmova reacts after a point against Ukraine's Elina Svitolina during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Slovakia's Viktoria Kuzmova hits a return against Ukraine's Elina Svitolina during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina celebrates her victory against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina celebrates her victory against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina celebrates her victory against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina serves against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina reacts after a point against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina hits a return against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

Ukraine's Elina Svitolina serves against Slovakia's Viktoria Kuzmova during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 17, 2019. (Photo by Jewel SAMAD / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Viktoria Kuzmova of Slovakia in action against Elina Svitolina (not seen) of Ukraine during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM

MELBOURNE, AUSTRALIA - JANUARY 17: Elina Svitolina of Ukraine in action against Viktoria Kuzmova (not seen) of Slovakia during Australian Open 2019 Women's Singles match in Melbourne, Australia on January 17, 2019. Svitolina won the match with 2-0. Recep Sakar / Anadolu Agency/ABACAPRESS.COM