It was a fantastic win, by any standards. After being broken early on, it seemed the man ranked 162 places below the Japanese would be having a brief first experience of Flushing Meadows.
But, after fighting back to parity, he showed great resolve to clinch the first set, repeating the trick in the second stanza before dominating what was ultimately the decider.
Before his stunning victory, Birmingham’s Evans had only ever appeared in two Grand Slam first round draws, both at Wimbledon after being granted home wild-cards.
Evans, the world number 179, is 23 years old but has only really risen to prominence in the last six months – he was outside the top 300 before then, yet another example of failed British potential.
The spark was the Davis Cup tie against Russia earlier this year. Evans was originally not selected for the clash, despite the absence of Andy Murray.
But he was surprisingly picked ahead of Jamie Baker, the British number three at the time.
A mammoth five-set defeat to Dmitry Tursunov, ranked around 250 places above him, proved to Evans that he could mix it with the top 100 players.
And a shock win over world no. 80 Evgeny Donskoy, which gave the Murray-less Britain a surprising 3-2 victory over Russia, proved he could beat them.
Impressive runs at Nottingham and Queen’s saw him invited to other prestigious tournaments, with the 5’9” right-hander getting to a couple of Challenger finals in the process.
While his movement through US Open qualifying was impressive, there was nothing to suggest Evans could dispose of one of the world’s top players with such ease.
His recent upsurge in form is down to a change in attitude, with Evans himself admitting he had been less than professional in the past.
"I’m from a pretty working-class background and there are always other things going on," Evans said back in April after his Davis Cup antics.
"I don’t train hard enough, I don’t work hard enough. I know that’s the reason. It’s my fault."
By all accounts Evans has changed his ways, with the influence of his electrician father coming to the fore. He is putting in the hard yards on and off the court, and – at 23 – has realised it is now or never if he is to make a living out of the game.
There was also a boost from the LTA, who took Evans down south ahead of the Davis Cup clash. The 'boot camp' experience appears to have worked.
"Evans is enjoying winning tennis matches more than he enjoys going out partying, and that's a recent change," Eurosport tennis expert Simon Reed said.
"That, combined with the LTA picking him for that Davis Cup tie, has seen the boost to his game. Since he moved down south earlier this year, he has found out just what it takes to become a proper professional.
"There was talk of him moving back to the Midlands, which I find very surprising - he has to stay within the system, to train down south with the LTA."
Evans is not the most physically imposing figure, so he needs to put in those hard yards just to compete with the bigger, fitter guys that dominate modern tennis. Good hands and reading of the game are not enough any more.
He is unlikely to threaten the latter rounds in New York. But Evans almost quit tennis last year, reportedly after taking his father’s criticism badly, so anything from now on is a bonus to a career that seemed to be going nowhere.
Evans has vowed to make a go of his year and, with the undoubted talent he has at his disposal, Britain could have a second man lighting up Grand Slams for the next few years - provided he stays out of the pub.
By Reda Maher / Follow on Twitter @Reda_Eurosport
- Sports & Recreation