Alexander Zverev believes his comeback victory over Novak Djokovic at the Olympics has paved the way for his fine start at the US Open.

Zverev came from a set down to defeat world number one Djokovic 1-6 6-3 6-1 at the semi-final stage in Tokyo, with the German going on to claim gold by beating Karen Khachanov in straight sets.

The world number four carried the winning form to Cincinnati, triumphing at the Western and Southern Open, and has made a smooth start at Flushing Meadows, where he lost out to Dominic Thiem in last year's final.

Zverev did not offer up a single break point in a dominant first-round win over Sam Querrey, and lost only four games when cruising past Albert Ramos-Vinolas 6-1 6-0 6-3 on Thursday.

"The process started at the Olympics for me, and the match against Novak," Zverev told reporters.

"That kind of started it off, because I was down badly, and I managed to win with great tennis.

"It was very important for me to kind of back it up in Cincinnati, because a lot of the times players that for the first time in their career win something really big like a grand slam title or a gold medal, they do tend to go downhill a little bit.

"So it was important for me to go to Cincinnati, to a place where I have never won a match before this year, and have a great tournament."

Another motivation for Zverev is the cruel fashion in which he lost to Thiem last year, when he surrendered a two-set lead.

"I mean I was the first man in 785 years to lose a US Open from two sets to love up and being a break up in the third set, serving for it in the fifth set, being two points away multiple times, it was painful," Zverev said with a smile.

"I still remember it, I remember it every single time I walk on this board but I take it as motivation because I'm back here to hopefully play a great tournament and win a grand slam title, that's what I’m here to do."

Zverev has now tallied up 40 wins in 2021 and 13 on the bounce, though the 24-year-old - who could meet Djokovic in the semi-finals - knows he has to maintain his strong service game to keep his best tennis.

"My serve is kind of the key to my game. When it's working I'm playing great. When it's not, I'm losing matches like I did at Wimbledon," he said.

"It's no secret that my serve is probably the most important shot in my game, and I'm happy with how it's working. The matches are not going to get easier and I will need that to be my weapon.

"I think it was always a problem of mine at the beginning of my career that I always spent a lot of hours, a lot of time in the beginning of grand slam tournaments. So it's nice to have two matches, winning [them] in straight sets."