Novak Djokovic hailed a US Open superfan as a "true entertainer" after he was joined on court for an impromptu dance following a straight-sets victory over Andreas Haider-Maurer.

The spectator is familiar to regulars at Flushing Meadows, entertaining crowds with his flamboyant performances in the Arthur Ashe Stadium stands.

But the shirt-swinging dancer was afforded a rare opportunity to set foot on the court on Wednesday following a 6-4 6-1 6-2 win for Djokovic in the second round.

"Yeah, I mean, I'm glad that he came down to the court," said Djokovic. "It was not planned. I'm happy for him. You know, he's a true entertainer.

"I know him for definitely five years. Each year I see him in one of my matches, dancing, taking down the layers of the T-shirts.

"But, you know, it never gets old. It's always good to see him dance, perform. He gets the crowd going in the night session in Arthur Ashe, which is always very unique for players and for fans."

Victory for Djokovic set up a third-round clash with world number 25 Andreas Seppi, who came from behind to see off Teymuraz Gabashvili.

"Seppi is somebody who has been around for many years," added Djokovic. "He has very solid game from the back of the court. If you allow him to play, he can play well.

"No question about it, he's got shots.

"He was, I think, top 15, top 20 in the world. He's been there for many years. He has experience.

"He's played on Arthur Ashe. He's not going to get overwhelmed by the occasion.

"I'm going to try to obviously impose certain tactics, trying to control the game and kind of set my own pace to that match."