Novak Djokovic loses in opening round of US Open for first time, falling in 5 sets to Mariano Navone

NEW YORK (AP) — Novak Djokovic grinded through physical and internal ailments, made one mistake after another and could not find what it took to beat a feisty, younger opponent who was not intimidated under the lights against tennis' most decorated player.

The 39-year-old is out of the U.S. Open after a first-round defeat to Mariano Navone on Sunday night, losing 7-6 (5), 5-7, 4-6, 6-2, 6-1 in a five-set marathon that lasted four hours and 36 minutes. It was the longest opening match of a Grand Slam in Djokovic's career and became his earliest exit in one in two decades, dating to the 2006 Australian Open. He had never lost in the first round at the U.S. Open.

With this defeat, 21 years to the day of his U.S. Open debut, the question now lingers as to whether this was Djokovic's final match at this or any Grand Slam.

Djokovic made 70 unforced errors in a painful performance that ended mere minutes before midnight.

The record holder with 24 major titles threw up at least once and later appeared to be cramping when he grabbed at his left foot. Djokovic swallowed pills brought to him by a doctor and had his lower back massaged during a medical timeout between the fourth and fifth sets, and he grimaced after several shots.

Throughout his time on court, it was clear Djokovic was not himself, and the wear and tear of sickness and soreness took its toll. The No. 4 seed from Serbia cruised to early 3-0 and 4-1 leads before blowing them and losing the first set — the first time that happened to him in the first round of the U.S. Open since '06.

With his wife, Jelena, watching from the stands with worried looks on her face, Djokovic had moments where he looked like one of the best to play the sport. His fist pump was reserved after winning the second set, and he put his hand to his ear and gestured to the crowd for applause on the way to taking the third.

But Navone — a 25-year-old from Argentina who earlier this year won his first ATP singles title — did not go away. After firing a shot wide in the fourth set, Djokovic landed awkwardly and dropped his racket.

Djokovic all but conceded the fourth set. But he was unable to muster enough for the what would have been his 43rd five-set victory as Navone picked up his first.

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