With four American men and four American women in the last 16, the home fans can dream of a Flushing Meadows trophy sweep no matter how far-fetched that idea might seem.
Not since 2002 when Pete Sampras and Serena Williams were crowned champions have Americans hoisted both trophies but, with Pegula, Coco Gauff, Taylor Fritz and Frances Tiafoe all top 10 seeds and in the last 16, the chance will be there.
Seeded third and carrying momentum from a solid run into Flushing Meadows that included a win at the Canadian Open, Pegula is rated the top US hope and has performed as expected, only dropping one set on her way to the fourth round.
After straight-set romps in her first two matches, Pegula received her first test in the form of gritty veteran Svitolina, a US Open semi-finalist in 2019.
Pegula had the only break in a tight opening set but that would be all she needed for a 1-0 lead.
In the second it was Svitolina finally getting her first break chance and making the most of the opportunity to pull level.
The deciding set also looked ready to swing on a single break and it went to Pegula who broke the 26th seed to go 3-2 up, sweeping four straight games to clinch her spot in style.
The last time Flushing Meadows had a chance to celebrate a homegrown women's champion was in 2017 when Sloane Stephens beat Keys in an all-American final.
Keys is back and making another run after taming 14th seed Liudmila Samsonova 5-7 6-2 6-2 to set up the clash with Pegula.
Sixth seed Gauff was the first to book her spot with a win over Belgian Elise Mertens on Friday, while Peyton Stearns beat Britain's Katie Boulter later on Saturday.
Elsewhere, an ailing Ons Jabeur scraped by Czech Marie Bouzkova 5-7 7-6(5) 6-3 to keep her latest US Open campaign on track in the third round on Saturday despite an error-riddled performance.
The Tunisian fifth seed said this week she was feeling like a "zombie" due to illness but came back from the dead to overcome a cool-headed Bouzkova, firing off 56 winners under the lights on Arthur Ashe Stadium.
"It's a very tough match from both of us," said Jabeur, last year's runner-up. "She didn't want to stop. I tried my best today and she's a great player."
Jabeur may be known as the "Minister of Happiness" but the perennial fan favourite had little to smile about in the opening set, as her mistakes quickly piled up and Bouzkova broke her on the fifth try in the fourth game.
The Tunisian broke back with a nice backhand slice in the ninth game but handed Bouzkova another break with a double fault on set point.
Down a break in the second set, Bouzkova took an off-court medical timeout after the seventh game with an apparent leg injury but kept up the fight even as she occasionally limped around the court, breaking back in the 10th.
Jabeur, who at times hunched over on the court in clear discomfort, found new life in the tiebreak, where she fired off crisp forehand winners to push the affair into a third set.
She got the critical break in the sixth set as Bouzkova double-faulted and nodded solemnly as the Czech hit a shot into the net on match point, sealing the nearly three-hour slugfest.
The Wimbledon runner-up said she had struggled to catch her breath early in the match but was grateful to be playing at all after suffering a foot injury in Cincinnati.
"Every match for me is a bonus right now," she told ESPN. "I'm discovering a part of myself."
She will next play China's Zheng Qinwen, who beat Italian Lucia Bronzetti 6-3 4-6 6-4, in the round of 16, and expects a big challenge having retired in their last meeting in Toronto in 2022.
"She kicked my ass," said Jabeur. "Learned a lot. She has a very good forehand... It's going to be a tough one, for sure."
