"Every win that I've been going through, it's been securing anyone's doubts or even my own doubts about whether I belong with these guys, playing these high-level tournaments", said Shapovalov, who beat Russia's Daniil Medvedev in the first round.
It was most unfortunate, particularly when Edmund's side of the draw was blown wide open by the exit of Marin Cilic, the... Then No. 4 Alexander Zverev lost to Borna Coric in the second round.
One of the fancied names crashed out, however, as Grigor Dimitrov was beaten by teenager Andrey Rublev. As they walked into the sparsely populated Arthur Ashe stadium, it was Edmund who knew his way around.
Former world number one Mats Wilander has hailed Denis Shapovalov stating that the Canadian teenage tennis star is a combination of Rafael Nadal and Roger Federer. Shapovalov is the player to watch at the 2017 US Open, where he sent veteran Jo-Wilfried Tsonga home early.
It was Edmund's 10th match in 14 days after reaching the semi-finals of the Winston-Salem Open and his heavy schedule perhaps caught up him.
Edmund's last appearance in the largest arena in world tennis 12 months ago had seen the Briton lose in straight sets to Novak Djokovic in the fourth round.
When play resumed it was evident that Edmund was in a bad way as Shapovalov won the next two games without dropping a point.
Federer, though, held his nerve to take it to a deciding set before making it through. He fended off 15-40 to serve out the set, 6-3.
And if Shapovalov ever wants a rematch, Wilson says he's more than willing. But once he had his eye in, he became increasingly dominant.
Shapovalov breached Edmund's serve in the fourth game of the second and maintained his advantage to level the match at a set apeace.
Midway through the set, after Edmund held to take a 3-2 lead, he went back to his chair and called for the doctor.
For the first few games, Shapovalov looked edgy. Yeah, there is a lot of new experiences, but, yeah, I mean, like I'm saying, everything kind of happens too quickly.
The Canadian Denis Shapovalov has made Friday a big splash in the Elite of world tennis by accessing the 8th finals of the US Open in 18 years.
Shapovalov advances to the Round of 16, where he'll face Spaniard Pablo Correño-Busta. It's a little bit easier the second time around and third time around.
Play continues at the US Open on Day Six, at 11am (4pm BST).
But Shapovalov steadied himself and came through in the tiebreaker, finishing with 28 winners to 19 unforced errors.
But the Croatian came into the tournament having not played a match since losing the Wimbledon final to Roger Federer because of an adductor problem. With the draw torn to shreds, he has as good a chance as anyone to stamp his mark on the second week of the tournament. But for me it's in the past and I'm a different person and a different player now.
"I just stayed calm and just waited for my next chance and took it".
- US Taps Strategic Petroleum Reserve After Hurricane Harvey
- Jays manager John Gibbons to miss O's game for personal reasons
- Leah Remini claims Scientology pressured her to convert Kevin James
- New entrant in union Cabinet, KJ Aphons an inspiration for country's youth
- No. 1 Alabama Takes On No. 3 Florida State In Marquee Opener
- Nebraska, Arkansas State Comes Down To The Final Play
- Mikel says he wants to qualify Nigeria to World Cup, AFCON
- Cambodia arrests opposition leader for 'treason'
- Kendall Jenner breaks silence over Pepsi ad controversy
- Another Windows 10 update due October 17