By Can Erozden
Elina Svitolina, the world no. 19 in women's tennis, retired on Monday from the Australian Open after an injury.
Ukraine's Svitolina, who faced 19-year-old Czech player Linda Noskova, suffered from a back injury in the first set forcing her to leave the contest. Noskova was on a 3-0 lead in a Round 4 match at Melbourne's Margaret Court Arena.
Noskova automatically qualified for the quarterfinals, where she will play against Dayana Yastremska, another player from Ukraine.
Noskova will play her first Grand Slam quarterfinal at the Australian Open.
Yastremska beat her Belarusian opponent Victoria Azarenka with the sets of 7-6 (8-6), 6-4 at Rod Laver Arena.
Two-time champion Azarenka was eliminated from this year's first Grand Slam.
In men's, Russian third-seed Daniil Medvedev qualified for the quarterfinals after he beat Nuno Borges from Portugal with the sets of 6-3, 7-6 (7-4), 5-7, 6-1 at Rod Laver Arena.
Medvedev will next take on Poland's Hubert Hurkacz.
The Australian Open will end with the men's final on Sunday.