Novak Djokovic’s first match at the US Open was a bit of a litmus test for the Serbian legend because he didn’t play a hardcourt warm-up tournament coming into the year’s final Grand Slam. The 24-time Grand Slam champion said he didn’t play the Cincinnati Open because he prefers to focus on the Grand Slams at this stage of his career.

Tennis icon Novak Djokovic once again etched his name in the record books after his opening win over Learner Tien in the US Open.

As a tennis veteran, Djokovic will know match sharpness is very different to playing practice sets, so it was no surprise that his physical levels collapsed mid-way through his match against the young and hungry Tien.