Nick Kyrgios knocked out of US Open in epic quarterfinal upset

Nick Kyrgios' quest for a maiden grand slam title is over after he was knocked out in a thrilling US Open quarterfinal. 

NEW YORK, NEW YORK - SEPTEMBER 04: Nick Kyrgios of Australia celebrates against Daniil Medvedev during their Men's Singles Fourth Round match on Day Seven of the 2022 US Open at USTA Billie Jean King National Tennis Center on September 04, 2022 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Mike Stobe/Getty Images)

That's it, it's all over. 

Nick Kyrgios' quest for a maiden grand slam title is over after he was knocked out by Karen Khachanov in an epic US Open quarterfinal on Wednesday (AEST).

The Russian played superbly in the crucial moments and claimed a thrilling 7-5 4-6 7-5 6-7 6-4 victory over five sets. 

Kyrgios was on the back foot after losing the first set and appeared to be nursing a niggling leg injury, calling for a medic after the first set. 

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"I can't walk without pain," he was overheard saying.

The Australian later told his box: "I don’t want to f****** play through this s***."

But Kyrgios managed to shake off the injury concern, playing through the pain and winning the second set to even the scores.

However, Khachanov quickly returned serve by winning the third set, putting himself one set away from booking his spot in the semi-finals.

Kyrgios then hit back, going to another level deep in the fourth set to win the tiebreak and force a decider.

But despite having the advantage of serving first in the fifth set, Kyrgios was immediately broken in the opening service game and never recovered. 

It was a typical Kyrgios performance as he relied on his huge serve and frequently let rip at his coach's box. 

But he only had himself to blame for blowing key opportunities to get the upper hand with countless unforced errors.

Kyrgios gifted Khachanov a break in the second set when he botched two questionable serve and volley attempts, before later handing his opponent a break back on a silver platter with a double fault. 

It's a hugely disappointing result for Kyrgios, who was in red-hot form and rated one of the favourites to win the US Open after he knocked out World No. 1 Daniil Medvedev in the fourth round while Rafael Nadal, Dominic Thiem and Stefanos Tsitsipas lost earlier in the tournament. 

The Aussie was furious after the match - smashing two racquets on the court in frustration in an epic tantrum. 

Remarkably, none of the players left in the men’s singles draw having ever won a grand slam singles title.

Khachanov will next play fifth seed Casper Ruud in the semifinals. 

It's all over. (Photo by Elsa/Getty Images)