Betrayed by his body and brought to tears, Novak Djokovic’s run at this U.S. Open is done before it got started.

The Greatest of All Time knocked out by Father Time.

And by Argentine Mariano Navone, who won 7-6 (5), 5-7, 4-6, 6-2, 6-1 in a 4-hour, 36-minute marathon. Djokovic waved to the fans as they cheered, and made a heart symbol as he left Arthur Ashe Stadium. Will it be for the last time?

Exactly 21 years to the day after Djokovic’s U.S. Open debut, it’s fair to ask whether this was his finale in Flushing? That’s how ugly it looked, and how compromised he was. Actually, make that how compromised he’s been.

Novak Djokovic is worked on during a break as he plays against Mariano Navone in the first round of the 2026 US Open Tennis Championship on Sunday, August 30, 2026. Corey Sipkin for the NY POST

“It was obvious that it was an awful feeling on the court for me,” said Djokovic, dealing with an ailment for some time. “It’s something that I’ve been carrying, unfortunately, pretty much every match this year: vomiting, throwing up, a serious issue there. Then my whole body starts to collapse, basically cramping and pain. Yeah, the back just gave up in the end and shoulder, and I couldn’t close it out.

“I was a break up in the fourth, but just struggled all the way since the fourth game of the match. Again, I don’t want to take too much out of his win. Congrats to him. He’s a nice guy, a fighter. But I didn’t enjoy myself.”

Asked if the issue was fixable, Djokovic replied “I don’t know. I’m trying, man. I’m trying. Let’s see.”

Djokovic had won 37 straight first and second-round matches here in the U.S. Open. He hadn’t lost this early in any Major in 20 years, since a first-round exit in Australia back in 2006.

But on Sunday, Djokovic made 70 unforced errors. He fought through at least three bouts of nausea, cramps, needed an inhaler, a medical timeout and two pills. But once his back seized up and his serve disappeared, this went from a match to a requiem.

And for the 48th-ranked Navone, the biggest win of his life.

“Novak is the GOAT in this sport. Beating him at the U.S Open, Arthur Ashe, is one of the first moment I have in tennis,” Navone said. “When you’re a kid and you’re thinking to play tennis, the biggest stage in the tennis world is very important for you. When you have the chance to play against him, you wish and you dream to beat him in these kinds of settings because you grew up with that. So yeah, it’s a dream come true. It was a pleasure.”

Novak Djokovic of Serbia reacts against Mariano Navone of Argentina during their Men’s Singles First Round match on Day One of the 2026 US Open. Getty Images

Djokovic, 39, was not just under the weather but some will say over the hill. He’d thrown up and needed treatment two weeks ago in Cincinnati, suffering with a mystery medical condition. Many will suggest the ailment is simply called age.

On Sunday, Djokovic vomited multiple times on the court and the towel box, and used an inhaler on the fourth set changeover. But it was the back that was the final straw.

Djokovic had a break lead in the fourth set when it tightened up. He only took one more game the rest of the way.

After taking a quick 3-0 lead early, he started to struggle physically.

Up 5-4, Djokovic called for a trainer who gave him a pill. But it didn’t keep Navone from taking the first set. Djokovic sailed a forehand long to give Navone set point; and when he drilled a forehand into the net, the Argentine had cashed in.

In the second set, Djokovic started to move better. Down 4-3, he won a 29-shot rally with a backhand down the line to go up 40-15, then held to knot the set at 4-all. He held, then took the third set 6-4.

Novak Djokovic vomits during his match against Mariano Navone at the US Open. ESPN

But after getting a cramp in his left foot in the fourth set, Djokovic’s back tightened up. It left his serve toothless, often in double digits. That’s when Navone took the last two games and the set 6-2.

Djokovic took a medical timeout. A trainer was ready to rub some sort of cream on his lower back, while a doctor gave him more pills. But after having taken the lead off free points he garnered on his first serve, that edge was now gone.

Mariano Navone returns a volley against Novak Djokovic in the first round of the 2026 US Open Tennis Championship in Arthur Ashe Stadium at the USTA Billie Jean King National Tennis Center on Sunday, August 30, 2026, in Queens, NY. Corey Sipkin for the NY POST

Navone pounced on that Achilles Heel and ended Djokovic’s stay in Flushing.

It remains to be seen if he’ll ever have another.