Just 24 hours after Prince Carlos was knocked off his perch, King Novak was dethroned.

Not since they chucked us Brits out in 1776 has America dispensed with royalty so rudely.

With the defending champion out in the third round, stunned by Alexei Popyrin, this US Open suddenly feels like anyone’s game.

It is often the way here in New York, with players arriving at the final post of the Grand Slam season in various states of exhaustion and disrepair.

Djokovic was a shadow of his former greatness and, in Popyrin, he faced an opponent who ran him close at both the Australian Open and Wimbledon this year. 

Australian star Alexei Popyrin (pictured) stunned Djokovic to win the contest in four sets

This time the Australian finished the job in four sets and the Montreal champion is among many who can now consider himself an outsider for this title.

The 25-year-old from Sydney was potent but Djokovic was startlingly bad. His serve was appalling, broken five times thanks in part to 14 double faults.

‘I have played some of the worst tennis I have ever played, serving by far the worst ever. It was just an awful match for me,’ he said.

Djokovic struggled during a miserable encounter as his US Open journey was ended

Saturday’s defeat at Flushing Meadows was Djokovic’s earliest defeat in New York since 2006

In seeking for an explanation for Djokovic’s terrible form, we must repeat the analysis of Alcaraz’s defeat by Botic van de Zandschulp and hark back to the recent Olympic final. 

Djokovic beat Alcaraz that day in Paris to win his first gold medal for Serbia, but the match took a heavy emotional toll on both men.

It was Djokovic’s earliest defeat in New York since 2006 and this is the first year since 2002 when none of Djokovic, Rafael Nadal and Roger Federer have won a Grand Slam title. It feels like the end of an era.

Expectation is building that the US Open may have an American men’s champion for the first time since Andy Roddick in 2003.