All of the top 10 women’s singles seeds have reached the Australian Open third round for the first time since 2007.
Fifth seed Elina Svitolina completed the set when she beat American Lauren Davis 6-2 7-6 (8-6) in a match that finished at 00:45 local time.
The Ukrainian, searching for her first Grand Slam title, will play Spanish two-time major champion Garbine Muguruza next.
Karolina Pliskova and Belinda Bencic were among the winners on day four.
Eighth seed Serena Williams won the title in 2007 when she was unseeded.
She will play Wang Qiang in the third round today, while defending champion Naomi Osaka takes on Coco Gauff in a rematch of their emotional US Open meetingin September.
Play was delayed on the outside courts on Thursday because of the dust and mud that came down during a rainstorm in Melbourne on Wednesday night.
On Margaret Court Arena, Swiss Belinda Bencic overcame Latvia’s Jelena Ostapenko in a fluctuating match to reach the third round.
The sixth seed, 22, lost four games in a row in both sets but still managed to win 7-5 7-5 against the 2017 French Open champion.
Muguruza progressed with a 6-3 3-6 6-3 victory over Australian Ajla Tomljanovic on Rod Laver Arena.
Czech second seed Karolina Pliskova had a straightforward 6-3 6-3 win over Germany’s Laura Siegemund and will play Russia’s Anastasia Pavlyuchenkova or American Taylor Townsend in the last 32.
American Catherine Bellis, ranked 600 in the world and playing at her first Grand Slam in two years after four surgeries, knocked out Czech 20th seed Karolina Muchova 6-4 6-4.
Bellis, who was was told she may have to quit tennis after struggling with wrist and elbow injuries, will next face Belgian 16th seed Elise Mertens who beat Britain’s Heather Watson 6-3 6-0.
Angelique Kerber, the 2016 champion in Melbourne, saw off Australian wildcard Priscilla Hon 6-3 6-2, while Carla Suarez Navarro, who will retire at the end of the season, lost 6-3 7-5 to Poland’s Iga Swiatek.
Dutch ninth seed Kiki Bertens overcame Australia’s Arina Rodionova 6-3 7-5 and 2019 semi-finalist Danielle Collins was beaten 6-4 2-6 7-5 by Yulia Putintseva of Kazakhstan.
Putintseva will face fourth seed Simona Halep after the Romanian two-time Grand Slam champion beat Britain’s Harriet Dart.
In the men’s category, World number one Rafael Nadal reached the third round of the Australian Open with a straight-set win over Argentina’s Federico Delbonis.
Nadal, bidding for a record-equalling 20th Grand Slam title, swept aside 76th-ranked Delbonis 6-3 7-6 (7-4) 6-1.
The Spaniard will face compatriot and 27th seed Pablo Carreno Busta next.
There were battling five-set wins for seeds Dominic Thiem and Karen Khachanov on the fourth day in Melbourne, and an entertaining victoryfor Nick Kyrgios.
Nadal has not won the Australian Open since 2009 but he has entered this year’s first Grand Slam as the top seed.