Novak Djokovic once again battled health issues in the early rounds of an American hardcourt tournament, just weeks after struggling with heat exhaustion in his harrowing second-round exit at the Cincinnati Open. The Serbian serial champion is the No4 seed at the US Open but began his travails in New York in challenging circumstances, showing signs of physical issues and dehydration as he vomited multiple times during the third set of his first-round match against Mariano Navone. Djokovic was in the sixth game when he was overcome with the issue, bending double at the back of the court as he voided his stomach. Despite throwing up again during the game, the 39-year-old held his serve, and want on to win his second set after dropping the first during an uncharacteristically error-strewn tiebreak. During the opening stages of the match – before the Arthur Ashe Stadium roof was closed due to inclement weather, Djokovic visibly struggled with the humid New York evening, rubbing his head with an ice bag and at times clutching his temples as if affected by a headache. In one of the early breaks in play, Djokovic went as far as to ask the supervisor if once the roof was closed, the air conditioning could be turned on. Djokovic is seen during a changeover in his first-round match against Mariano Navone Djokovic dropped the first set before rallying to win the next two on Sunday in Queens When play restarted following the roof’s closure, Djokovic took two tablets given to him by a tournament physio as he continued to grapple with the early stages. Deep in the third set, Djokovic was also able to take on fluids shared with him by his team seated courtside, as his camp attempted to find a solution as the match ticked towards its fourth hour. In the stands, Djokovic’s wife Jelena looked desolate as her husband battled both his opponent and his own body, at times putting her head in her hands as she watched the match play out. After his defeat in Cincinnati to another Argentine, Thiago Agustin Tirante, Djokovic revealed that in recent years he had struggled with the heat more than ever after developing a health condition that has affected him ‘for the past couple of years’. ‘(It causes) a lot of issues, especially when it is humid and it is hot,’ Djokovic said in his post-match press conference. ‘I did anticipate it, but there are all these things, like nerves and everything involved that make it worse, and that’s what happened.’ In Flushing Meadows however, the further Djokovic found himself from his on-court puke, the more he imposed himself on the world No49.Frequently drawn into long pushing battles with the clay-court specialist, after winning the third set Djokovic was quick off the mark in the fourth with an early break in a bid to stamp out Navone’s fight. But the Argentine proved he was down but not out with an immediate break-back which left Djokovic shaking his head in disbelief.