Novak Djokovic reacts during a match against Mariano Navone, at the 2026 US Open at USTA Billie Jean King National Tennis Center in New York City, Sunday. (AFP-Yonhap) NEW YORK (AFP) -- Novak Djokovic suffered his earliest Grand Slam exit in 20 years Sunday and said he does not know how to solve the physical problems he has battled in "pretty much every match" this year.Argentina's Mariano Navone defeated Djokovic 7-6 (7-5), 5-7, 4-6, 6-2, 6-1, ending the Serbian's latest bid for a record 25th Grand Slam title. The loss also snapped Djokovic's streak of 78 consecutive first-round victories at Grand Slam tournaments, dating to his defeat by Paul Goldstein at the 2006 Australian Open.Djokovic vomited on the court and struggled with cramps and back pain late in the match -- an "awful feeling" to which he is becoming accustomed."It's something that I've been carrying, unfortunately, pretty much every match this year. Vomiting, throwing up. ... Then my whole body starts to collapse, basically cramping and pain."Although he reached the Australian Open final this year and the Wimbledon semifinals, Djokovic said he is not currently equipped to make deep tournament runs -- and is unsure how to address the problem."I'm just trying to address really what's going on and how far I can go this way," he said.Despite his struggles, Djokovic appeared to have finally taken control when he broke Navone for a 2-1 lead in the fourth set with a vintage backhand winner down the line.But Navone won the next five games, raising his arms in celebration after saving two break points to take a 5-2 lead and then breaking Djokovic again to force a fifth set.Djokovic took a medical timeout before the final set, receiving a massage on his back and another dose of medication.Navone raced to a 3-0 lead in the deciding set. Despite the encouragement of the crowd, there was no way back for Djokovic as Navone dropped only one point on his serve on the way to victory."It's unbelievable," an ecstatic Navone said after defeating his longtime idol in their first meeting, a match that lasted four hours and 36 minutes."It was a tough match, a battle. Playing against Novak the first time in the biggest stage we have in the world of tennis right now. ... Like, until 20 years he never lose in the first round, so I mean, it's crazy."Navone, ranked 48th, was particularly pleased with his mental performance."I was two sets to one down, and then break down also in the fourth, but in that moment I felt it," he said.Djokovic broke Navone in the second game and moved ahead 3-1 in the opening set.But Djokovic was clearly struggling. As Navone gained confidence, Djokovic had to escape a 0-40 deficit to hold for 4-1 and appeared increasingly weary as the rallies grew longer.Djokovic double-faulted on break point, allowing Navone to cut the deficit to 4-3. After a brief delay to close the roof when showers began, Navone held at love to tie the set at 4-4.Neither player yielded before the tiebreaker, but medication delivered by a trainer did not alleviate Djokovic's sluggishness.Djokovic fell behind 4-2 in the tiebreaker. After hitting a sharply angled forehand winner to tie it at 5-5, he sent one forehand long and another weakly into the net to hand the set to Navone.In a tense second set, Djokovic missed break opportunities in the third and fifth games before breaking Navone at love for a 6-5 lead. He then held at love to even the match at one set apiece.The third set brought more of the same, with Djokovic appearing exhausted after every long rally.He squandered a valuable break opportunity in the fifth game. After Navone held for a 3-2 lead, Djokovic nearly collapsed into his courtside chair and buried his face in a towel.Djokovic continued and was rewarded with a crucial break for a 5-4 lead. He held serve to take a two-sets-to-one advantage but could not make the lead stand.After breaking Navone for a 2-1 lead in the fourth set, Djokovic lost the next eight games.When the match ended, Djokovic embraced Navone before leaving the court while blowing kisses to the crowd that had tried to will him to victory."So grateful to experience this," he said of the crowd's support. "They were trying to lift me up in important moments. ... The love and appreciation they gave me in the end really touched my heart."