Novak Djokovic has been dumped out of the US Open following a five-set defeat to Mariano Navone in the first round.

In search of a record 25th grand slam title, the 39-year-old lost 7-6 (7-5) 5-7 4-6 6-2 6-1 in a battle that lasted four hours and 40 minutes, with Djokovic struggling physically towards the end.

Although Djokovic raced into a 3-0 lead in the first set with an early break, Navone levelled at 4-4 before winning the set via a tie-break.

Djokovic responded well in the second, not giving up any break points before converting one of his own in the 11th game, allowing him to serve for the set.

And the Serbian looked set to progress after a break in the 10th game of the third saw him take a 2-1 lead in the match, though Navone refused to lie down.

After the pair exchanged breaks early on in the fourth, Navone converted two further breaks to take the first-round tie to a decider.

Djokovic was visibly struggling in the fifth, vomiting into a towel box and tearing up as Navone sealed a huge upset with his first match point.

"I think it was obvious that it was an awful feeling on the court for me," Djokovic said.

"I don't want to take too much out of Mariano's win. Congrats to him, he's a nice guy and a fighter - but I didn't enjoy myself.

"It's something that I have been carrying pretty much every match this year - vomiting, throwing up.

"And then my whole body starts to collapse basically, cramping and pain - the back just gave up in the end and shoulder, and I couldn't close it out."

1 - With victory over Novak Djokovic, Mariano Navone has now:

 become the first player to defeat Djokovic in the R128 at the US Open
 become the first to defeat Djokovic in the R128 at a Grand Slam since Paul Goldstein (AO 2006).
 claimed a first ATP top 10 win at Grand… pic.twitter.com/8aNj9sylo1

— OptaAce (@OptaAce) August 31, 2026

Navone will be joined in the next round by Daniil Medvedev, who defeated Hugo Gaston 6-4 6-2 6-4 at Flushing Meadows.

Home favourite Tommy Paul also progressed with a 6-7 (3-7) 6-1 6-3 6-3 win over Chak Lam Coleman Wong.

Cameron Norrie, meanwhile, lost 6-7 (6-8) 6-2 6-2 6-3 in the opening round to France's Luca van Assche.

Djokovic given reality check in quest for grand slam record

For the first time in his career, Djokovic has lost in the opening round at the US Open, while it was his first round-of-128 defeat at any grand slam since the 2006 Australian Open.

Djokovic was taken to five sets in the opening round of a major for the first time since the 2010 US Open, when he defeated Viktor Troicki, though Navone emerged victorious on this occasion.

It marked the Argentine's first ATP top-10 win at a grand slam event, with Matteo Berrettini or Stan Wawrinka awaiting in the next round.

For Djokovic, this will serve as a harsh reality check, with age clearly catching up to one of the all-time greats.

He remains level with Margaret Court on 24 grand slam titles, though it remains to be seen whether Djokovic can compete at the highest level.