Ailing Novak Djokovic suffered his earliest Grand Slam exit in 20 years on Sunday, falling in five brutal sets to Mariano Navone in the first round of the US Open. The 48th-ranked Argentine's 7-6 (7/5), 5-7, 4-6, 6-2, 6-1 victory ended Djokovic's latest bid for a record 25th Grand Slam title. It also ended his run of 78 Grand Slam first-round victories, a streak stretching all the way back to Djokovic's 2006 loss to Paul Goldstein at the 2006 Australian Open. Djokovic was seen vomiting on court and struggled with late-match cramps but 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 fighting off two break points for a 5-2 lead and breaking Djokovic again to force the fifth set. Djokovic took a medical timeout before the final set, receiving massage on his spine and another delivery of medication. But Navone jumped to a 3-0 lead in the decisive set and there was no road back for the Serb as his opponent dropped just one point on his own serve as he sprinted to the finish line.