MELBOURNE (AFP) - Serena Williams will attempt to join sister Venus in the Australian Open last 16 on Saturday(Jan 21), as Rafael Nadal looks to show who's boss against exciting young gun Alexander Zverev.
The American 22-time Grand Slam winner faces compatriot Nicole Gibbs as she tries to keep up her momentum towards the tournament second week, after two comfortable wins so far.
Williams, who lost last year's final to Angelique Kerber, said she had been trying to channel positive thoughts as she targets a seventh Australian title, which would give her an Open-era record 23rd major.
"I know that being Serena on the court is in a way being calm, which is in my name, but always having that fire as well," she said, explaining her approach.
"I think, most of all, being confident." If Williams gets past Gibbs, the second seed will next play either 16th seed Barbora Strycova or 21st seed Caroline Garcia.
Another veteran gunning for more Grand Slam glory is Spain's Nadal, who is attempting to improve on an injury-riddled 2016.
The 14-time Grand Slam winner's comeback will be given a testing examination by top-rated Zverev, who is hoping to join older brother Mischa in the last 16.
"He is of the best players of the world, without a doubt, today," Nadal said of the German teen.
"His potential is so, so high. I know I have a very tough match, and I know I need to play my best if I want to have chances." If the German beats the 2009 champion, the Zverevs would become just the third pair of brothers to reach the round of 16 at a Grand Slam in the Open era.
Gene and Sandy Mayer at 1979 Wimbledon, and Emilio and Javier Sanchez at the US Open in 1991 were the others.
Giant-killer Denis Istomin is back in action, keen to build on his stunning upset of six-time Australian champion Novak Djokovic in the last round.
He faces Pablo Carreno Busta, seeded 30, on an outside court, with the winner due to meet either Richard Gasquet or Grigor Dimitrov, who play in the evening on Rod Laver Arena.
The Zverevs are two of three Germans to reach the third round, along with Philipp Kohlschreiber who takes on sixth seed Gael Monfils on Margaret Court Arena.
In an intriguing women's match, Britain's ninth-seeded Johanna Konta meets former world number one Caroline Wozniacki, with both players in fine touch.
"It will be an incredibly tough one. Every round so far has been," said Konta, who made the semi-finals last year.
US Open finalist and fifth seed Karolina Pliskova has a late match on Margaret Court Arena against Latvian Jelena Ostapenko, while sixth seed Dominika Cibulkova is up against Ekaterina Makarova.