Melbourne - Home favourite Nick Kyrgios steps up his charge for a first Grand Slam title when he plays Karen Khachanov in the Australian Open third round on Saturday.

The flamboyant but temperamental 23rd seed is enjoying growing popularity after leading fundraising for Australia's bushfires crisis, but he faces a tough match-up in the Russian 16th seed.

Kyrgios showed new composure in his testing win over Gilles Simon and hopes are high that he will take another step towards ending Australia's 44-year wait for a homegrown men's champion.

If he beats Khachanov, Kyrgios could face a mouthwatering showdown in the last 16 with Rafael Nadal, the man he disparagingly labelled "super salty", part of a long-running feud.

But first the world No 1 takes on Pablo Carreno Busta as he goes in search of a record-equalling 20th Grand Slam title.

Nadal has a strong record against his fellow Spaniards, owning a 17-match winning streak dating back to his first-round shock against Fernando Verdasco at the 2016 Australian Open.

He has only dropped one set in four meetings with Carreno Busta, his Davis Cup team-mate, making him hot favourite to join defending champion Novak Djokovic and Roger Federer in the last 16.

However, after converting only three out of 20 break points in his straight-sets win over Federico Delbonis in round two, Nadal said he needed to be more clinical.

"I need to play better. Especially I need to convert the break points," said Nadal, who is on the trail of Federer's record for Grand Slam titles.

"I have been practising every day a little bit better. I am confident that I am going to play better because every day in the third set I have been able to show a good level of tennis."

Wimbledon champion Simona Halep will look to charge forward in a women's draw vacated by Serena Williams - who was shocked by China's Wang Qiang on Friday - when she plays Kazakhstan's Yulia Putintseva.

Karolina Pliskova, the second seed, faces Anastasia Pavlyuchenkova, fifth seed Elina Svitolina plays two-time Major-winner Garbine Muguruza and Angelique Kerber, the 2016 champion, is against Italy's Camila Giorgi.