Novak Djokovic defeated Daniil Medvedev in straight sets on Sunday to win his fourth US Open and a record-equalling 24th Grand Slam singles title, cementing his claim as the greatest tennis player in history.

The 36-year-old Djokovic won 6-3, 7-6 (7/5), 6-3 to become the oldest men's champion in New York in the Open era and match Margaret Court's all-time mark for most Grand Slam victories.

"I don't know where to start. It obviously means the world to me," said Djokovic, wearing a white jacket with the number 24 on his chest during the trophy presentation.

"It's hard to describe. I'm really living my childhood dream to compete at the highest level in this sport.

"I never imagined I would be standing talking about 24 Grand Slams but the last couple of years I've felt I have a chance and I have a shot at history and why not grab it."

The Serbian is the first man to win three Grand Slam events in the same season four times, crowning his impending return to world number one in the most fitting of ways inside Arthur Ashe Stadium.

The victory added to his wins at the Australian and French Opens earlier this year, with the only blemish his five-set defeat to Carlos Alcaraz in the final of Wimbledon in July.