NICK KYRGIOS tossed a sports bottle onto the court and confronted fans as he finished his season in the quarterfinals of the US Open in New York.

The Aussie was beaten 7-5, 4-6, 7-5, 6-7, 6-4 by solid Russian Karen Khachanov in an absorbing clash at Arthur Ashe Stadium.

When he finished the match, Kyrgios broke two rackets and spat in the direction of his box; It was unacceptable behavior from a very sore loser.

The 27-year-old was unable to back up his thrilling victory over world number one Daniil Medvedev two days earlier, as he was beaten in five sets at 1 a.m. local time on Wednesday morning.

Kyrgios, who had a medical timeout with a suspected knee problem after losing the first set, seemed off, always fun to watch on any occasion and this was no exception.

There was a trademark racket strike on the ground in the third set and he constantly groaned on his box at the seeming lack of support from him.

The World No. 25 received a warning for unsportsmanlike conduct from British referee James Keothavong after he dropped a sports bottle on the ground before the start of the fourth set.

One of the staff members had to get down on one knee and clean up the spill before the game could continue.

And in the fourth and fifth sets, Kyrgios complained about screaming fans before he was about to serve and during rallies.

Keothavong had to remind the audience that he respect the two players, but a few ignorant ignored his words.

He certainly got rowdy at times, but most of the crowd wanted Kyrgios to progress.

Over the course of three hours and 34 minutes, high-quality tennis was on display as the two players delivered 60 aces – 31 from Kyrgios and 30 from Khachanov – at breakneck speed.

Kyrgios, who lost to Novak Djokovic in the Wimbledon final, plans to return to Australia to see his family.

He has said this fortnight that he is unlikely to return to the ATP Tour until at least January, when he begins the countdown to the Australian Open in Melbourne.

There is a possibility that Kyrgios could fly back to Europe in November to play his friend Thanasi Kokkinakis in doubles at the ATP Finals; they qualified due to his win at the Australian Open in January.

And he could combine that trip with an appearance for Australia if he reaches the Davis Cup final later that month in Malaga in November.

But for now, it looks like he'll hang up his racket for several months, return to Oz and recharge his batteries after a busy summer on grass and hard courts.

Speaking after the loss, Kyrgios said: "Obviously I'm devastated. But all the credit goes to Karen. He's a fighter. He's a warrior."

“I just feel like he was winning all or nothing at all. I feel like I just failed this event right now. Honestly, I don't even care about any other tournament.

“Now to be successful at a Grand Slam, it's like no other tournament really matters.

“I think almost every other tournament during the year is really a waste of time. You should run and perform at a Grand Sl