Serena Williams Australian Open 2015
Serena Williams celebrates a point during her third round match against Elina Svitolina at the Australian OpenReuters

A frustrated Serena Williams was a picture of torment for a set and a half before she found her range to fend off Elina Svitolina 4-6, 6-2, 6-0 and reach the fourth round of the Australian Open on Saturday.

The top seed entered Rod Laver Arena with a frown and grumbled as she miscued groundstrokes and had little penetration on her first serve against the 26th-seeded Ukrainian.

However, she dug herself out of the hole and sealed the match in 99 minutes with a searing cross-court return.

The American will next play Garbine Muguruza for a place in the quarterfinals.

In the men's section, top seed Novak Djokovic overcame a nervous start and feisty Fernando Verdasco to safely negotiate his way into the fourth round.

With the surprise loss of Roger Federer still hanging over the men's draw, Djokovic was well aware the danger the 31-year-old Verdasco, a former top-10 player posed.

The Spaniard had taken Rafael Nadal deep into the night in a five-hour, five set marathon during the 2009 semifinals in Melbourne and only trailed the Serb 6-4 in their career head-to-head record.

Verdasco harassed Djokovic at the start but once the world number one sealed the first set tiebreak after an hour of the tense baseline battle, he ran away with the match in the next two to win 7-6 (8), 6-3, 6-4 and set up a fourth round clash with Luxembourg's Gilles Muller.

Defending champion Stan Wawrinka avoided the same fate that befell compatriot Federer on Friday with a comfortable victory over Finland's Jarkko Nieminen to move into the Australian Open fourth round.

The 29-year-old Swiss, appearing on Rod Laver Arena virtually 24 hours after Federer had been shocked by Andreas Seppi on the same court, did not allow the tricky left-hander any opportunities to do the same in the 6-4, 6-2, 6-4 win.

Wawrinka actually had major troubles with his first serve, with it hovering at less than 50 percent for much of the match, but still managed to win his service games and dominate the majority of the short rallies.

He will now meet either Guillermo Garcia-Lopez in the fourth round after the Spaniard beat Canada's Vasik Pospisil.

Results (third round): Men's singles: Guillermo Garcia-Lopez (Spain) beat Vasek Pospisil (Canada) 6-2, 6-4, 6-4; 4-Stanislas Wawrinka (Switzerland) beat Jarkko Nieminen (Finland) 6-4, 6-2, 6-4; 12-Feliciano Lopez (Spain) beat Jerzy Janowicz (Poland) 7-6 (6), 6-4, 7-6 (3); 8-Milos Raonic (Canada) beat Benjamin Becker (Germany) 6-4, 6-3, 6-3.

Women's singles: Madison Brengle (US) beat Coco Vandeweghe (US) 6-3, 6-2; 11-Dominika Cibulkova (Slovakia) beat 19-Alize Cornet (France) 7-5, 6-2; 1-Serena Williams (US) beat 26-Elina Svitolina (Ukraine) 4-6, 6-2, 6-0; 18-Venus Williams (US) beat Camila Giorgi (Italy) 4-6, 7-6 (3), 6-1; 24-Garbine Muguruza Blanco (Spain) beat Timea Bacsinszky (Switzerland) 6-3, 4-6, 6-0; 6-Agnieszka Radwanska (Poland) beat 30-Varvara Lepchenko (US) 6-0, 7-5.