The Spaniard's improvisational style stands in stark contrast to Djokovic's cold-blooded efficiency and despite the 16-year age gap between them Alcaraz says they bring out the best in each other's games.

"Every time that we step on the court, we play really high (level) tennis," Alcaraz told reporters after his first round win at the US Open on Tuesday.

"Every time that we face each other, it has been a really good and intense match."

A changing of the guard appeared complete earlier this year when the 21-year-old Alcaraz thrashed 24-time Grand Slam champion Djokovic in the Wimbledon final in July to defend his crown and capture his fourth major title.

But fortunes can change quickly in tennis.

Alcaraz was almost inconsolable after falling to Djokovic in the Olympic final at Roland Garros earlier this month, saying he felt that he had let down Spain.

Djokovic described winning the Olympic gold medal as his "biggest sporting achievement".

"We have a really good friendship off the court," Alcaraz said. "We talk a lot in the lockers every time that we see each other around.

"Once we step on the court, there are no friends here on tour, but after that, after the court, I have a really good relationship with a lot of players, and one of them is Novak."

With Djokovic seeded second and Alcaraz third, the pair could be on a collision course to meet in the final in the frenzied atmosphere of New York.

"New York, it's crazy," Alcaraz said.

"I love playing here. The crowd gives you an energy that probably you don't feel in other courts."

--Reuters--