Former U.S. Open champion Stan Wawrinka said he still had the game for the grandest stage after the Swiss veteran became the oldest man to win a singles contest at the tournament since a 40-year-old Jimmy Connors in 1992.

The 38-year-old Wawrinka, who claimed the last of his three Grand Slam titles at New York in 2016, rolled back the years to outclass Japan's Yoshihito Nishioka 7-6(5) 6-2 6-4, moving with ease despite foot issues that have plagued him in recent years.

"I think I'm playing well. I'm not trying to compare from the past because it's never good idea to compare a few years ago what I was doing," Wawrinka told reporters. "But I'm happy with my level. I know where I am right now.

"I know I can beat some really good players. I can be really competitive. I'm moving well. Today was a great match. A really high level, high intensity. I'm happy to get through in three sets. Most important is to keep going in the right direction.

"The last few months have been almost better every week with more wins, with more confidence with what I'm doing. Hopefully I can keep pushing myself and get some big results before the end of the year."

Wawrinka made his comeback to the tennis circuit in March 2022 after more than a year out following two operations on his left foot, returning to the top 100 in the world earlier this season to currently sit 49th.

He said he had no intention of slowing down in the twilight of his career.

"You also want to push yourself to the maximum, be the better player, best as possible. Of course you're going to have up and downs in your career, with some positive emotions when you win, some tough ones when you lose," Wawrinka said.

"That's also one of the main reasons I keep going, to get those emotions. Hopefully a positive one.

"I never forgot why I started playing tennis and what I was dreaming when I was young ... to play the U.S. Open, play Grand Slams, big tournaments, ATP tournaments, to be there. I'm happy I can still play at that level."