Alexander Zverev is riding a wave at the US Open after his confidence-boosting win over world number one Novak Djokovic en route to claiming gold at the Olympic Games.

Zverev survived a first-set scare to power past Lloyd Harris 7-6 (8-6) 6-3 6-4 in Wednesday's US Open quarter-final.

The German fourth seed will face either Djokovic, who is bidding to become just the third man to complete a calendar Grand Slam and first since 1969, or Matteo Berrettini for a spot in the men's final at Flushing Meadows.

Zverev – last year's US Open runner-up – said he has been fuelled by his semi-final win over Djokovic at the Tokyo Games.

"It's the biggest tournament in the world, Tokyo. It's the Olympics," Zverev said during his post-match news conference.

"Winning there against the world number one, especially that I was down a set and a break, being kind of out of the match, then coming back, it was different than the other matches. The emotions were different.

"Also securing a medal for Germany was very special to me. This year it seems like nobody can beat him in a big match, nobody can beat him at the grand slams.

"I feel like I was the first player to beat him in a very big match this year. That does give you something. To any person it would give you something.

"As I said before also, I think it was very important for me to back it up in the finals, back it up in Cincinnati. Hopefully I can continue this streak."

Zverev is in the midst of a career-best 16-match winning streak and has clinched 37 of 40 sets on the hard courts after winning Olympic gold and his fifth career ATP Masters 1000 crown in Cincinnati.

The 24-year-old is bidding to become the second man in history to win Olympic gold medal and the US Open/US Championships title in the same season, after Andy Murray in 2012.

On preparing against Djokovic, Zverev added: "You have to be perfect, otherwise you will not win.

"Most of the time you can't be perfect. That's why most of the time people lose to him. Against him, you have to win the match yourself. You have to be the one that is dominating the points. You have to do it with very little unforced errors.

"He is the best player in the world. He is very difficult to beat. But he's still also got to win tonight. He's playing Matteo Berrettini who is in very good form, finals of Wimbledon. I think he's looking forward to that match, as well. It's going to be an interesting match to watch those two."