A furious Novak Djokovic halted his warm-up to confront a fan after apparently being subjected to jibes ahead of his third-round US Open match against American rival Denis Kudla.

Top seed Djokovic was preparing for his late-night encounter with Kudla when he appeared to take issue with something said from the crowd behind him.

The Serb broke off from serving to confront the fan, and while footage of the exchange did not pick up all of what was said, it did show Djokovic warning: “I’ll come find you. Trust me, I’ll come find you.”

Djokovic, 32, brushed aside the incident as well as concerns over a shoulder injury to beat the unseeded Kudla 6-3 6-4 6-2, setting up a fourth-round clash with 2016 tournament winner Stan Wawrinka of Switzerland.

When asked after the match about the incident with the fan and why he had vowed to “come find” him, Djokovic replied: “To have a drink. I liked the guy. I’m going to buy him a drink.”

He also credited the fan with providing added motivation for his clash with home favorite Kudla.

“I think he did me a favor. Even maybe he didn’t want to do me a favor, he did me a favor, big favor,” Djokovic added.

The Serb is aiming to defend the title he won last year and clinch a fourth US Open overall. Despite having 16 Grand Slam titles to his name, Djokovic has had strained relations with the New York crowd down the years, and often does not enjoy the same level of adulation of ‘Big Three’ rivals Roger Federer and Rafael Nadal.

READ MORE: ‘People have to wake up to Djokovic’s greatness’ – Becker as Serb claims 16th Grand Slam

Elsewhere on Friday night, Russian Daniil Medvedev was involved in a running spat of his own with fans, after he appeared to give them the middle finger during his third-round win over Feliciano Lopez.

Medvedev, 23, later mocked the booing crowd by claiming they had given him the “energy” to win the match.