MELBOURNE (AFP) - Showman Nick Kyrgios blasted Frenchman Gilles Simon off court at the Australian Open on Thursday (Jan 23), with his raw talent shining through in front of an adoring home crowd.

The 24-year-old had the measure of the veteran early on, then lost concentration and became agitated before refocusing to win 6-2, 6-4, 4-6, 7-5 on his favoured Melbourne Arena.

It set up a third-round clash with either Russian 16th seed Karen Khachanov or Sweden's Mikael Ymer, with the winner of that match on course to meet world No. 1 Rafael Nadal in round four.

"I definitely lost my way a little bit... but I decided to refocus," Kyrgios said of his mini-meltdown in the third set. "I could have gone to a very dark place in the fourth set but I put it away."

At night, top seed Rafael Nadal laboured past dogged fellow left-hander Federico Delbonis to take another step towards only a second Australian Open crown.

The Spanish world No. 1 created 20 break-point chances but was constantly denied by the Argentinian before he wrapped up a 6-3, 7-6 (7-4), 6-1 win on Rod Laver Arena.

The victory set up a third-round clash with countryman Pablo Carreno Busta, his doubles partner at this month's ATP Cup.

"It was a tough match. I lost a lot of opportunities on break point but found a way to finally win the second set," he said. "In the third I was more relaxed, more aggressive and found better play in that set."

Nick not just playing for himself

A seemingly more mature Kyrgios has spoken of how the bush-fire crisis in his homeland has given him perspective and focus, and that he felt he was playing for the nation rather than just himself.

And with the roars of the crowd ringing in his ears, he broke the Frenchman in the first game and consolidated by holding serve.

Kyrgios looked sharp and broke again for 5-2 then served out the set, sending down five aces and, crucially, making only two unforced errors.

Simon was struggling with his serve and the Australian broke again for a 1-0 lead in the second set, making some big shots when it counted.

It went with serve before Kyrgios, watched again by his ATP Cup captain Lleyton Hewitt, won the set with another rocket serve.

He broke Simon again early in the third set, letting out a huge "C'mon!" But the Frenchman broke back as Kyrgios started to lose concentration in game eight, berating himself and gesturing to his box as frustrations kicked in.

He lost the set as his focus drifted and he yelled at his box: "Of all the things you could say, 'Stay tough'. Thanks man, thanks. That's what I get, every break point, 'Stay tough'. Wow."

However, the Australian conquered his mental demons to regroup, getting a crucial break to go 6-5 up in the fourth and completing victory with a big ace, his 28th of the match.

Against the 76th-ranked Delbonis, Nadal had dropped only 10 games in three previous emphatic wins and defeat was never on the cards at Melbourne Park.

But the Argentinian, whose best Grand Slam result was the third round in Melbourne in 2016, made life hard for the 19-time Grand Slam winner, fending off 16 break point chances.

Nadal looked on track for another straightforward victory after racing through the opening set, sealing it with a trademark cross-court forehand. But he found it tougher going in the second, which went with serve up to the tiebreaker.

Nadal, though, came through and Delbonis never recovered as the Spaniard asserted his authority to race home, but not before hitting a ballgirl on the head with a ball. He rushed over to console her and gave her a kiss for good measure.

"For her it was not a good moment, I was so scared for her, the ball was quick and straight on her," Nadal said. "I'm very happy she is good. She is brave. Well done."

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.

While he has won 12 titles at Roland Garros, four at the US Open and two at Wimbledon, his only triumph in Australia came in 2009 when he beat Roger Federer, with four runner-up finishes to his name. If he does win a second title on Feb 2, Nadal will equal the 20 Grand Slams crowns held by great rival Federer.