Djokovic stunned in US Open first round by Navone

Novak Djokovic made his earliest exit at the U.S. Open after a shock 7-6(5) 5-7 4-6 6-2 6-1 loss to unseeded Argentine Mariano Navone in a gruelling first-round clash on Sunday, as his latest bid for a record 25th Grand Slam title went up in smoke.

The 39-year-old, who vomited during the match and struggled to serve towards the end due to a back issue, was in tears shortly before Navone sealed victory.

It marked the first time the Serb had lost in the opening round of a Grand Slam since the Australian Open in 2006.

Navone revelled in the biggest win of his career and was stunned to have beaten a player he considers the greatest of all time (GOAT).

"Five sets, against the GOAT, it's not something you do every day. I'm very happy," Navone said on court.

"It means a lot to me. It's a dream come true. Now I have to recover. It's almost 12 a.m. We have to go to sleep."

Djokovic had arrived for his 20th appearance at the Grand Slam with questions over his form and fitness after losing to Thiago Agustin Tirante in his Cincinnati opener two weeks ago.

He raced to a 3-0 lead in the opening set in humid conditions but Navone pulled level at 4-4 after a short delay during which the roof of the main showcourt was closed as rain fell at Flushing Meadows.

With the fourth seed still looking uncomfortable, world number 49 Navone forced a tiebreak and claimed the set to draw loud cheers and gasps from the crowd.

Djokovic, a four-times champion in New York, dug deep to take the second set, and after vomiting into a courtside bin during the third set he looked to have recovered, breaking 25-year-old Navone for a 5-4 lead before closing out the set despite a shaky game on serve.

But Navone responded by claiming the fourth set as Djokovic's serve deserted him towards the end due to a back issue, and the Argentine held his nerve in the decider to complete a famous win in four hours and 36 minutes.