'True inspiration': Rafael Nadal's touching post-match tribute to Kobe Bryant

Rafael Nadal and Nick Kyrgios left everything out on the court in their gruelling four-set match on Monday night and both also paid their respect to NBA legend Kobe Bryant.

Kobe Bryant died on Sunday when a helicopter crashed into a hillside in Calabasas, California.

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The helicopter crash killed nine people including his daughter, known as Gigi, with a fellow player and parent on her travel basketball team.

And both Nadal and Kyrgios paid their respect to the Lakers great after the Spaniard ended the Aussie’s gallant Australian Open campaign with an enthralling four-set, fourth-round victory at Melbourne Park.

The so-called grudge match of the Open was played out in good spirits between the two feuding rivals, as Nadal prevailed 6-3 3-6, 7-6 (8-6), 7-6 (7-4) in a centre-court thriller on Monday night.

In a touching tribute to Kobe Bryant, Kyrgios entered into Rod Laver Arena in a LA Lakers No.8 singlet, seemingly in tears, and proudly warmed up in it.

Following the match, Nadal put on a Lakers hat and paid his respect to the NBA legend.

“Super sad, he is one of the greatest sportsman in history,” Nadal said.

“He deserves a round of applause.

“He has been a true inspiration for the world of sport and for a lot of kids. This is one of those days you want to forget, but of course Kobe Bryant will be in our hearts and minds for the rest of our lives.”

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The world No.1's reward is a quarter-final meeting on Wednesday with fifth seed Dominic Thiem in what will be a sequel to the past two French Open finals won by the Spaniard.

"It was a very tough match. Since like in the beginning I was a little bit under control (but) against Nick you are never under control," Nadal said after denying Kyrgios by the exact same scoreline as he did last year at Wimbledon.

The NBA tragic started sluggishly, dropping serve in the fourth game as Nadal parcelled up the opening set in 36 minutes.

Saturday night's four-hour, 26-minute epic against Karen Khachanov, the longest match of Kyrgios's career, looked to have taken a toll.

He had to stave off three more break points in the opening game of the second set, before suddenly exploding to life.

The fist-pumping underdog leapt into the air in jubilation after breaking Nadal with an inch-perfect lob and surging to a 4-1 lead.

The advantage was enough for Kyrgios to level the match at one set apiece.

Fighting desperately to become the first Australian to conquer the top seed at Melbourne Park since Mark Philippoussis brought down Pete Sampras in 1996, Kyrgios threw his body at everything as the pair went toe to toe.

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But there wasn't a hint of bad blood, Nadal even giving Kyrgios the thumbs up at one point when the gallant home hope lay prone on Rod Laver Arena after an exhausting 24-shot rally.

Kyrgios saved his best serve for a linesperson, furiously questioning the umpire why the official was laughing after getting a call wrong that Kyrgios successfully challenged.

He saved his worst serve for the pivotal third-set tiebreaker, gifting Nadal a set point with a wild double-fault.

Nadal incredibly returned the favour, only for Kyrgios to net a backhand to hand the top seed the set.

The writing seemed on the wall when he dropped serve for a second time to fall behind 3-1 in the fourth set.

But he made one last stand, breaking Nadal when the Spaniard served for the match at 5-4 in the fourth set.

It was merely a stay of execution, Nadal again holding his nerve in the breaker to advance to his 41st grand slam quarter-final after three hours and 38 minutes.

"I just feel happy that I won one more match tonight, an important one," said the 19-times major champion.

"That gives me the possibility to keep going on this tournament. Possibility to play one more time on this amazing court and that makes me happy - what more can I say?"

A quarter-finalist in 2015, Kyrgios must console himself with a projected return to the world's top 20 for the first time since August of 2018 after bowing out in the fourth round for the second time in the past three years.

"When he is playing like today with this positive factor, he gives a lot of positive things to our sport," Nadal said.

"I encourage him to keep working like that, because he is one of the highest talents."

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With AAP