Melbourne, Jan 21 (IANS): Top-10 seeds Barbora Krejcikova of the Czech Republic and Maria Sakkari of Greece advanced to the Australian Open fourth round in contrasting styles, defeating Latvia's Jelena Ostapenko and Russia's Veronika Kudermetova, respectively here on Friday.

Trailing by a set and a break, Krejcikova, the 2021 French Open singles and doubles champion, showed her mettle with a 2-6, 6-4, 6-4 comeback win against Ostapenko, the 2017 French Open champion, in the third round.

Unable to find her rhythm in the first set-and-a-half due to the sustained aggression from Ostapenko's racquet, Krejcikova trailed 6-4, 3-1 before taking the match into the decider. She broke Ostapenko in the first game of the third set and held onto the lead for the duration of the two hour, 10-minute encounter.

"I feel really proud with the way how I was able to handle the match even I was losing and I was really down," Krejcikova told wtatennis.com after the win. "The match was very difficult. I'm really happy that I was able to find a way how to use my chances and how to win it at the end."

Krejcikova will next face another former major-winner in No.24 seed Victoria Azarenka of Belarus, who dropped just two games in her third-round win over No.15 seed Elina Svitolina of Ukraine 6-0, 6-2.

Sakkari was back in the last-16 of the Australian Open after two years with the world No. 8 winning 11 of the last 12 games in a 6-4, 6-1 third-round victory over No.28 seed Kudermetova, booking her spot in the second week without the loss of a set.

"It has been a great start, not dropping a set, not getting too tired in my first matches, just finishing the matches in time," Sakkari said.

Sakkari will next face American Jessica Pegula, the No.21 seed and 2021 quarterfinalist, who defeated Spain's Nuria Parrizas-Diaz, 7-6(3), 6-2.

Spain's Paula Badosa quashed a comeback by Marta Kostyuk of Ukraine to reach the round of 16 for the first time. Americans Madison Keys and Jessica Pegula also advanced. Badosa had to work hard to make her first career round-of-16 showing at the Australian Open. The Spaniard survived a second-set comeback by Kostyuk before eking past the Ukrainian teenager 6-2, 5-7, 6-4.

Next up for Badosa will be former top-10 player Madison Keys of the US. Keys reached the round of 16 for the fifth time in her career by overcoming Wang Qiang of China 4-6, 6-3, 7-6(2).