Six years after debuting at Flushing Meadows and on her third attempt, Hon finally broke through with a 6-3 7-5 victory over Frenchwoman Leolia Jeanjean on Monday (Tuesday AEST).
The 27-year-old qualifier was left overjoyed.
"It's my favourite slam apart from the Australian Open so, yeah, can't be much happier right now," Hon said.
"I love New York, everything about it. Like the fans, everyone that comes to watch, there's so much energy and it's so chaotic and there's so much happening.
"But I'd way rather that than just silence, so there's something about it that gives me a lot of energy and it makes me want to like do well."
Hon will hit a new career-high after the tournament but isn't done yet, vowing to go out swinging against Russian 17th seed Liudmila Samsonova.
"Obviously she's an unreal player. She's got a very big game, so I know the ball will be coming fast like me," Hon said.
"I played her a couple of years ago, and I did win that one. I remember that. So, yeah, I mean I have nothing to lose.
"I feel good on these courts and I'll just go out there and not think too much of it being second round of the US Open and just think of it as another match."
Fellow Brisbane battler Walton also sent a more-fancied French opponent packing, taking down 22nd seed Ugo Humbert 6-4 7-6 (7-4) 5-7 6-1 for the biggest win of his career.
"It's up there," Walton said.
"At a slam, to beat a seeded player and it's a first win and you take great confidence in doing so.
"So obviously very happy with the win."
Walton's victory follows a titanic win over former world No.1 and 2021 US Open champion Daniil Medvedev in Cincinnati and will send the 26-year-old to a career-high of at least No.74 in the world.
"I've had a great American summer," he said.
"I feel more comfortable being back on the hard courts, and I'm just glad that this American summer I've really been able to capitalise on some good matches and some good wins.
"Last year was was horrible. I didn't win a match.
"But I'm just feeling very happy with where my game's at right now."
Hon and Walton can look forward to the biggest pay days yet, a minimum $US154,000 ($A237,000).
Walton has a huge opportunity to go even deeper in the draw.
He next faces Hong Kong qualifier Coleman Wong, the world No.176, for a place in the last 32 at a slam for the first time.
Daria Kasatkina gave Australia a third winner on day two, the 15th seed outclassing Romanian Elena-Gabriela Ruse 7-5 6-1.
Kasatkina will next play former Russian compatriot Kamilla Rakhimova.
The trio join Jordan Thompson in the second round.
But Aleksandar Vukic, James Duckworth and wildcard Talia Gibson all bowed out.
Vukic lost a three-and-three-quarter-hour thriller 6-3 6-7 (4-7) 6-4 3-6 6-4 to American Jenson Brooksby, Duckworth succumbed 7-5 6-3 6-4 to US wildcard Tristan Boyer and Gibson fell 6-2 6-2 against Polish 28th seed Magdalena Frech.
Big guns Alex de Minaur, the men's eighth seed, and Alexei Popyrin open their campaigns on Wednesday (AEST).
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