The Spanish top seed came through 6-3, 3-6, 7-6, 7-6 in the fourth round at Melbourne Park to continue his bid for a 20th Grand Slam title.

He had not dropped a set in the first three rounds but 23rd seed Kyrgios gave him his toughest test so far in front of his home crowd.

It was an intriguing encounter as the players have a frosty relationship with each other.

Kyrgios mimicked Nadal's serving routine when given a time penalty in his third round victory over France's Gilles Simon.

Nadal also accused the Australian of "lacking respect" after he served underarm against him at the Mexico Open in February, with Kyrgios accusing the Spaniard of being "super salty".

"I think I played well from the baseline, changing directions, changing rhythms, playing aggressive with my forehand and backhand," Nadal, looking to add to his 2009 Australian Open win, said.

"The problem is when he's serving, you don't have many chances. 

"You are under pressure the whole match."

Austria's fifth seed Dominic Thiem is waiting for Nadal in the last eight after he defeated France's 10th seed Gaël Monfils 6-2, 6-4, 6-4.

Swiss 15th seed Stan Wawrinka, the 2014 champion, out-lasted Russia's fourth-seed Daniil Medvedev in a five-set duel.

Wawrinka, a three-time Grand Slam champion, won 6-2, 2-6, 4-6, 7-6, 6-2.

He is now set to play Germany's Alexander Zverev, the eighth seed who knocked out Russia's 17th seed Andrey Rublev 6-4, 6-4, 6-4.

In the women's event, Romania's Wimbledon champion Simona Halep continued her progression.

The fourth seed, aiming for a third Grand Slam crown and a first in Australia, beat Belgium's 16th seed Elise Mertens 6-4, 6-4.

"It's a great performance by me to play the quarter-finals again, it's really nice to enjoy tennis here in Australia," said Halep, the runner-up in Melbourne in 2018.

"I'm really happy to go through."

The Romanian is now set to meet Estonia's Anett Kontaveit after the 28th seed came from behind to beat Poland's Iga Świątek, 6-7, 7-5, 7-5.

Kontaveit will contest her first Grand Slam quarter-final.

Russia's 30th seed Anastasia Pavlyuchenkova recovered to knock-out Germany's 17th seed Angelique Kerber in three sets.

The match ended 6-7, 7-6, 6-2 as the 2016 Australian Open champion and three-time Grand Slam winner was beaten.

Pavlyuchenkova is now due to meet Spain's two-time Grand Slam champion Garbiñe Muguruza, who knocked out Dutch ninth seed Kiki Bertens 6-3, 6-3.