As Novak Djokovic battles cramps, pain and early Grand Slam exits, is his dream of a 25th major and a 2028 Olympic farewell slipping away?

The 39-year old battled vomiting, back trouble and humidity before Mariano Navone completed a five-set upset in the US Open first round. | Tennis News

The four-time champion US Open battled for nearly five hours in the first round but was beaten by Argentina's Mariano Navone