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.

Novak Djokovic improved to 19-0 in the first round of the U.S. Open, battling through some leg troubles to beat Learner Tien 6-1, 7-6 (3), 6-2 on Sunday night.

It took a few extra hours, but Benjamin Bonzi pulled off the upset. After nearly blowing a two-sets-to-love lead, which was highlighted by a photographer inadvertently interrupting play with Bonzi serving for the match in the third set against No. 13 seed Daniil Medvedev, the Frenchman hung on in a dramatic fifth set.

The first-round match between No. 13 seed Daniil Medvedev and Benjamin Bonzi Sunday night at the US Open turned chaotic when, of all things, a photographer prematurely stepped onto the court as Bonzi served for the match.