OREANDA-NEWS Rafael Nadal's hopes of a third Grand Slam title of the year ended at the US Open as the Spaniard crashed out to unfancied American Frances Tiafoe on Monday night in what has been dubbed tennis' 'upset of the year'.

With Russian defending champion Daniil Medvedev gone after being beaten by Nick Kyrgios at the weekend, Nadal also failed to make it past the last 16 and guaranteed that there will be a new king of New York.

Nadal's performance appeared to be affected by the abdominal strain that saw him withdraw from a Wimbledon semi-final date with Kyrgios earlier this summer, with the four-time US Open winner starting on the wrong foot by conceding the first set 6-4. 

Fighting back to take the second set by the same margin, Nadal scrapped but ultimately lost the third and fourth sets 6-4 and 6-3 as Tiafoe wrapped up victory in a three-and-a-half-hour tussle.

"I'm beyond happy, I'm almost in tears. I can't believe it," said a clearly moved Tiafoe, 24, in his post-match interview.

"He's definitely one of the greatest of all time. I played unbelievable tennis today, but I really don't know what happened.

"I came out not giving Rafa all the respect, I came out to win a tennis match in front of you guys," beamed the Maryland native.

While Tiafoe will go on to play his second career Grand Slam quarterfinal against Russia's Andrey Rublev on Wednesday, and is the first male American since finalist Andy Roddick in 2006 to get as far in the tournament, Nadal's showing sparked whispers of retirement that the 36-year-old neither confirmed nor defused in his never-say-die manner.

"I am going to try to be ready mentally," Nadal revealed. "When I feel that I will be ready to compete again, I will be there.

"Tennis is a sport of position. You need to be very, very quick and very young.

"I was not able to create the damage I used to do," he confessed.

"The difference is easy: I played a bad match and he played a good match. At the end that's it," Nadal also said.

"I was not able to hold a high level of tennis for a long time. I was not quick enough on my movements. He was able to take the ball too many times very early, so I was not able to push him back."

With the Spaniard handed his first Grand Slam defeat of 2022 and the earliest at a major tournament in five years, someone not named Rafael Nadal or Novak Djokovic will get their hands on the last piece of top silverware on offer this year with Kyrgios and Rublev now among the favorites.

While Rublev plays Tiafoe in the quarterfinal, Kyrgios will have to take care of another Russian in Medvedev's compatriot Karen Khachanov in order to reach the last four.

Despite his defeat, 22-time Grand Slam champion Nadal could still return to the top of the ATP ratings at the end of the action in New York, provided that neither of Carlos Alcaraz or Casper Ruud reach the final.