Melbourne - Rafael Nadal will step up his bid for a record-equalling 20th Grand Slam title when he faces Argentina's Federico Delbonis at the Australian Open on Thursday.

The Spaniard can only count one Melbourne title among his 19 Majors but he will be confident of reaching the third round at least after winning all three previous meetings with Delbonis.

Swiss great Roger Federer, winner of 20 Grand Slam tournaments, and eight-time Australian Open champion Novak Djokovic are already through after straightforward wins.

Nadal has dropped only 10 games to 76th-ranked Delbonis in their previous meetings but he's not immune to Grand Slam shocks, losing four times to players ranked 100 or lower.

Victory in Melbourne would make Nadal the first man in the Open era - and only the third in history - to win all four Major titles twice, after Roy Emerson and Rod Laver.

Later on Thursday, Nick Kyrgios faces Frenchman Gilles Simon as he looks to become the tournament's first home-grown men's champion since Mark Edmondson in 1976.

Kyrgios is known for his combustible nature but after spearheading fundraising efforts for Australia's bushfire crisis he has cut a relatively calm figure in Melbourne - so far.

"I'm just playing for a lot more than myself. I've said it before... there's not necessarily added pressure. I feel like I'm playing for a lot of people," he said.

The 2014 champion Stan Wawrinka takes on Italy's Andreas Seppi and world No 5 Dominic Thiem is up against Australia's Alex Bolt, ranked 135 places lower.

In the women's draw, Wimbledon champion Simona Halep takes on Britain's Harriet Dart, and 2016 Melbourne winner Angelique Kerber faces Australia's Priscilla Hon.