With Djokovic and Alcaraz both out, who will win the US Open title?

NEW YORK — Another day, another stunning upset at the US Open.

Just 24 hours after Carlos Alcaraz was handed his earliest exit at the tournament, defending champion and No. 2 seed Novak Djokovic lost to No. 28 seed Alexei Popyrin, 6-4, 6-4, 2-6, 6-4, in the third round on the same court.

Playing in the prime-time night match Friday at Arthur Ashe Stadium, few thought the 25-year-old Australian had a chance against Djokovic, who was on a quest to make history with a record-breaking 25th major title, and had just won Olympic gold in Paris. They had met twice in majors this season — at the Australian Open and Wimbledon — and Popyrin had been unable to win in either match.

But Friday was different.

Perhaps still riding the momentum from winning his first Masters 1000-level title at the Canadian Open earlier this month, and buoyed by his 50 winners on the night and Djokovic’s poor serving, Popyrin played the best match of his career.

“It’s unbelievable because I’ve been in the third round about 15 times and I haven’t been able to get to the fourth,” Popyrin said on the court after the match. “To be able to do it against the greatest of all time is unbelievable. It’s a great feeling and the hard work paid off.”

Djokovic, who had knee surgery in June, later called his performance “awful” and said it was “some of the worst tennis” he had ever played. The 37-year-old admitted he felt drained after an intense summer schedule, which saw multiple surface changes.

“I spent a lot of energy winning the gold, and I did arrive to New York just not feeling fresh mentally and physically,” Djokovic said. “But because it’s the US Open, you know, I gave it a shot and I tried my best. I mean, I didn’t have any physical issues. I just felt out of gas, you know, and you could see that with the way I played.”

Djokovic officially concluded his Slam season without a title for the first time since 2017. It’s the first season a member of the Big Three (Djokovic, Rafael Nadal and Roger Federer) didn’t win a major trophy since…