Djokovic keen to have fun but fully focused on winning at US Open

Novak Djokovic blew off some steam following Tuesday's U.S. Open win by belting out a rendition of a Beastie Boys classic and the second seed said he was trying enjoy his time on court despite the pressure he faces to keep winning.

The 36-year-old, who is looking to match Margaret Court's all-time record of 24 Grand Slam titles, powered past American Taylor Fritz 6-1 6-4 6-4 at Arthur Ashe Stadium to reach a record 47th major semi-final.

Appearing more relaxed in his post match interview, Djokovic sang, '(You Gotta) Fight for Your Right (to Party)' with fans in the stands joining along.

"I'm trying to enjoy the moments on the court, but there's so much stress and pressure going on that it's hard to have fun, so to say, on the court," Djokovic told reporters.

"It's really about finding a way to navigate through the match and win a match for me, you know.

"But off the court, in terms of the actual journey of still being a professional tennis player and going around the world, travelling with my coaching team, we try to keep things light and have fun and enjoy life."

The Serbian said he expects a "great battle" in the semi-finals on Friday against the winner of the all American meeting between Frances Tiafoe and Ben Shelton.

"Both of the guys ... Shelton and Tiafoe, have a lot of charisma," Djokovic said. "They bring a lot of energy on the court. They're very quick, very powerful.

"I have couple days off. It actually serves well for my body at this stage of the tournament. I'll be ready whoever is across the net."