Rafael Nadal beats Nick Kyrgios to reach Australian Open quarter-finals

Spaniard made to work by fiery opponent on Rod Laver Arena before sealing a 6-3, 3-6, 7-6, 7-6 victory and set up clash against Thiem

Rafael Nadal celebrates after his four-set victory over Nick Kyrgios at the Australian Open. Reuters

World No 1 Rafael Nadal weathered a fierce storm from gutsy showman Nick Kyrgios on Monday to set up an Australian Open quarter-final against Dominic Thiem.

The Spanish top seed came through a riveting clash on Rod Laver Arena 6-3, 3-6, 7-6, 7-6 to end the gallant hopes of the basketball-mad Australian, who came on court wearing an LA Lakers shirt in honour of Kobe Bryant, who was killed in a helicopter crash on Sunday morning.

"What can I say about Nick? When he is playing like today with this positive attitude he gives a lot of positive things to our sport," said Nadal, the 2009 champion who is looking to match Roger Federer's record of 20 Slam crowns.

"He's one of the biggest talents we have on our tour and I like the Nick Kyrgios during the whole of this tournament."

It was billed as a grudge match after a series of bad-tempered exchanges last year when Nadal accused Kyrgios of lacking respect and the Australian fired back that the Spaniard was "super salty".

But Kyrgios struck a conciliatory tone beforehand, calling Nadal "a hell of a player", and it was played with respect from both sides.

The Australian said he was "shattered to lose" but hailed Nadal for "the champion he is, the player he is" and said he was working hard to keep up his new-found positivity.

"The trouble for me is being able to actually just produce the same attitude over and over again," he said. "I feel like I've made progress as a human. A tennis player, I don't really care about as much.

"I want to keep going in this direction, for sure... the trouble for me is being able to actually just produce the same attitude over and over again.

"I mean, hopefully I can keep doing it. I'm just taking it day by day, trying to be positive, just bring positive vibes."

As for taking on Thiem next, Nadal said: "It will be a tough match, we know each other very well, he's a great character, a fighter and hits the ball very well.

"I am moving in the right direction though and hopefully this victory gives me more positive feelings."

Fifth seed Thiem kept his flawless record against Gael Monfils intact with a trouble-free 6-2 6-4 6-4 victory.

Thiem, twice a French Open finalist, came into the fourth-round clash against the 10th seed having won all five of the matches they have previously played and did not face a single breakpoint against the Frenchman on the Rod Laver Arena.

Nick Kyrgios arrives on court wearing the jersey of former Los Angeles Lakers player Kobe Bryant, ahead of his match against Rafael Nadal. EPA

"I think that I played my best match so far of this Australian Open. A very, very good feeling," the Austrian said.

"The score looks way easier than the match was. I think I was lucky to make an early break in each set and then was managing to hold my serve well. I'm so happy because I'm for the first time in the quarter-finals here."

Germany's Alexander Zverev ended the hot streak of his close friend Andrey Rublev of Russia to reach the Australian Open quarter-finals for the first time.

The seventh seed broke once in each set for a clinical 6-4, 6-4, 6-4 win in just 1hr 37mins to go into a match-up with Stan Wawrinka, who defeated Russia's Daniil Medvedev.

Zverev retains his 100 per cent record over Rublev, who came into the match on a 15-match winning run including titles in Doha and Adelaide earlier this month.

After a long embrace at the net, Zverev, 22, said: "I've known him since we were 10 years old. I just reminded him how far we got together.

"A lot of young kids would dream about playing the fourth round of a Grand Slam against one of his closest friends. I just told him we're going to play a lot of great matches."

Former champion Wawrinka said his win over world No 4 Medvedev was his best match since knee surgery threatened to derail his career.

The popular Swiss star, who beat Rafael Nadal in the 2014 final, dug deep to come from behind in five intense sets and win 6-2, 2-6, 4-6, 7-6, 6-2.

"I think last time I played so well was before the surgery. I think for sure, I feel since the off-season my level is really high. Physically I'm moving better than last year. So I'm improving," he said.

A lengthy absence from the tour meant his world ranking plunged, but he has climbed back to world No 15 after runs last year to the last eight at Roland Garros and the US Open.

He said tennis was still his passion, with no signs of retirement despite being 34. "I'm playing, traveling around the world, playing in front of people, getting a lot of emotion from it.

"I love the process, also the way you have to try to improve, the time you need to put in the practice court to get to your level," he said. "I don't know how many years left. I want to do the maximum with it."