Iga Swiatek said she was "really proud" to reach her first US Open quarterfinal but the world No 1 was forced to dig deep to beat Jule Niemeier in the fourth round on Monday.
French Open champion Swiatek recovered from a set and a break down to see off her 108th-ranked German opponent, 2-6, 6-4, 6-0.
Top seeded Swiatek will face Jessica Pegula for a place in the semi-finals after the American eighth seed cruised past two-time Wimbledon champion Petra Kvitova 6-3, 6-2.
In a mistake-riddled clash on Louis Armstrong Court, there were a total of 15 double faults, 12 breaks of serve and 76 unforced errors.
"It's really satisfying. This is my first quarter-final in New York so I am really proud of it," said Swiatek, who becomes the first Polish woman to reach the last eight in New York.
Wimbledon quarter-finalist Niemeier hadn't won a hardcourt match in her career before coming to New York, but she went into Monday's match not having dropped a set and was fired up to repeat her Wimbledon journey where she had also beaten world No 2 Anett Kontaveit.
The 23-year-old from Dortmund swept through the opener with breaks in the first and seventh games. She then held her nerve in an eight-minute second game of the second set, saving two break points.
Niemeier sensed a shock victory when she broke for 2-1 but Swiatek eventually prevailed, taking a set which featured seven breaks of serve in 10 games.
In the decider, the Pole raced to a 4-0 lead with the powerful Niemeier only winning five points.
Moments later Swiatek completed victory with her 19th 'bagel' set of the season to wrap up a place in a third Grand Slam quarter-final of 2022.
Swiatek said her success in 2022 has been helped by her rigid loyalty to her walk-on play list which includes AC/DC, Led Zeppelin and Pearl Jam.
"I have been listening to it all year and I am pretty bored with it," she said. "But I am not going to change now."
Aryna Sabalenka is also through to the women's quarterfinals after the sixth-seeded Belarusian fought back to beat American Danielle Collins 3-6, 6-3, 6-2. She will face Karolina Pliskova for a place in the semi-finals after the Czech came through a battle of former world No 1s with Victoria Azarenka 7-5, 6-7, 6-2.
