The world number 179 cruised through the first round at Flushing Meadows by upsetting 11th seed Kei Nishokori 6-4 6-4 6-2.
Evans believes that his extra training at the start of the year is finally starting to pay off following the result.
"When I saw the draw it was a little bit daunting but I went out and I played a good game and he didn't react that well to how was playing," Evans told Sky Sports News. "I've just been on the practice court a lot more and in the gym a lot more. It's been a gradual process from January onwards and I'm reaping the rewards of it now.
"I was playing well coming into qualifying. I hadn't played that may qualifiers of grand slams and definitely hadn't won many matches in them.
"To go through three matches was an achievement in itself but I didn't want to stop there, I wanted to push on a bit. That's where the points for my ranking keep going up so it was good to come through today."