What happened on day nine?published at 07:12 Greenwich Mean Time 21 January
Iga Swiatek raced past lucky loser Eva Lys in 59 minutes to set up a quarter-final with eighth seed Emma Navarro, who clinched a narrow 6-4 5-7 7-5 win against Russian Daria Kasatkina.
American 19th seed Madison Keys knocked out 2023 runner-up Elena Rybakina with a 6-3 1-6 6-3 win to reach the quarter-finals.
Keys will face Ukraine's Elina Svitolina, who stormed to a 6-4 6-1 win against Russian Veronika Kudermetova.
In the men's draw, defending champion Jannik Sinner struggled physically before moving past Denmark's Holger Rune.
Sinner will take on Australia's Alex De Minaur after the eighth seed claimed a 6-0 7-6 (7-5) 6-3 over American Alex Michelsen.
Italy's Lorenzo Sonego beat American qualifier Learner Tien 6-3 6-2 3-6 6-1 to reach his first Grand Slam quarter-final.
Sonego will play 21st seed Ben Shelton next after the American's fourth-round opponent, Frenchman Gael Monfils, retired while trailing 7-6 (7-3) 6-7 (3-7) 7-6 (7-2) 1-0.