Nick Kyrgios' staggering 35-year first in win over Daniil Medvedev

Nick Kyrgios has become the first player in 35 years to beat a World No.1 twice in the same year after his victory over Daniil Medvedev at the US Open.

Kyrgios stormed into the quarter-finals in New York for the first time in his career after an extraordinary 7-6 (13-11) 3-6 6-3 6-2 victory over Medvedev on Sunday.

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It marked the Aussie star's fourth victory over Medvedev in five career meetings, as well as his third win over a World No.1.

The first came in 2014 when he shocked Rafa Nadal at Wimbledon as a teenager, with the second coming against Medvedev at the Canadian Open last month.

With his two wins over Medvedev in the last three weeks, Kyrgios is the first player since Pat Cash in 1987 to record two victories over a World No.1 in the same year.

Kyrgios' compatriot Cash beat Ivan Lendl twice when the American great was at the top of the rankings 35 years ago.

"It was an amazing match," Kyrgios said in his on-court interview.

"Obviously Danill is defending champion. A lot of pressure on his shoulders, but I played really well. I've been playing amazing for the last couple of months.

"But what a place - packed house in New York, I'm extremely blessed. I'm just really happy and hopefully I can keep it going."

The loss is a devastating blow for Medvedev, who will now lose his No.1 ranking because he was defending 2000 points from winning the US Open last year.

Depending on results, the new World No.1 could be Rafa Nadal, Carlos Alcaraz or Casper Ruud.

Nick Kyrgios storms into quarter-finals at US Open

The 27-year-old Kyrgios, who has won 20 of his last 23 matches and made the Wimbledon final in July, will next play another Russian in Karen Khachanov for a semi-final berth.

Khachanov equalled his best performance at a grand slam by defeating Spanish 12th seed Pablo Carreno Busta in a three-hour, 21 minute five-set thriller.

The 27th-seeded Khachanov dug deep to down Carreno Busta 4-6, 6-3, 6-1, 4-6, 6-3 at Louis Armstrong Stadium.

With Kyrgios' former long-time girlfriend Ajla Tomljanovic also advancing with a 7-6 (10-8) 6-1 win over in-form Russian Liudmila Samsonova, Australia now has a men's and women's quarter-finalist in New York for the first time since Cash and Wendy Turnbull in 1984.

In an explosive encounter laced with controversy and drama, Kyrgios risked being defaulted and overcame a running verbal battle with the chair umpire before ousting the top seed Medvedev.

Medvedev fumed at the umpire for not warning Kyrgios after the Australian went within centimetres of hitting a ball into the first row of the stands - and likely a spectator - after dropping the second set.

Medvedev then threatened to quit the match if someone from Kyrgios' courtside entourage wasn't ejected for disrupting him between his first and second serves.

"They cannot do it," Medvedev raged.

"If they do it a second time, I am not playing they're out, until somebody is out."

with AAP

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