Hours later, her cohort and friend Madison Keys clinched the last semifinal spot with a win over Kaia Kanepi, marking the first all-American final four in Flushing Meadows since 1981 and the first time in any Grand Slam since 1985.
Now, she is a quarterfinalist at the U.S. Open, where she will face top-seeded Karolina Pliskova on Wednesday.
"I'm going to have to serve really well", she said. "The team works as hard as I do". So I think we're all cheering for each other. "There was definitely the fear that a lot of players have struggled coming back from it".
"I mean, I don't care. I don't think there is anything else I'd rather be doing". "So this feels really good".
Keys had the ideal start to the second set as she capitalized on her third break point in the opening game, placing herself in an advantageous position for the victory.
Yet endurance is also a quality that Kanepi has shown, having nearly quit the sport after suffering Epstein-Barr virus and plantar fasciitis, which caused her to miss almost two years, per David Kane at WTA Tennis. The quarterfinals are scheduled to begin on Tuesday.
Perseverance seems to be a common thread among the Americans left in the field.
Two-time champion Venus Williams is the only one of the four to win a Grand Slam title, but her last victory in NY came in 2001 when she defended the title she won in 2000. It was Vandeweghe's first U.S. Open fourth round.
"This pressure, what I had here, this tournament, it was something new for me". I had to sit down and all that stuff. "I never thought, that I will live to see this day. Yeah, I think I'm just going to have to stay at my highest level and just wait for my opportunities when they come".
Vandeweghe spoke of facing Keys, who she lost to twice this summer.
Venus Williams returns a shot during her fourth round match against Carla Suarez Navarro on Sunday. Yet the lone remaining former US Open champion in the field and the oldest woman in the top 300 has made the second week at a seventh consecutive major - and remains the only woman to play in two major finals this year.
The Czech has been beaten in straight sets 7-6, 6-3 by American Coco Vandeweghe but was philosophical about her loss.
But Pliskova was back to her best in a 45-minute demolition.
"It's only been three" quarterfinals, total, Querrey said. "You grow and you learn and you adjust to the moments". But I'm firmly a person that lives in the future. Her first and third round matches against compatriot Alison Riske and 10th seed Agnieszka Radwanska were particularly testing, both of which she won in three sets. "I'm about, 'Is this win happening today?'"