China's Zheng Qinwen thrashed fifth seed and last year's US Open runner-up Ons Jabeur 6-2, 6-4 on Monday to reach her first Grand Slam quarter-final.
The 20-year-old Zheng meets Aryna Sabalenka, who is set to become the new world number one, or Russian 13th seed Daria Kasatkina in the last eight.
"Right now I feel just super happy and excited to play in a big stadium. I had a really good performance today," said Zheng, the 23rd seed.
"Ons is a fantastic player and really tough to beat. It's a really impressive win for me."
"I know my game has to be aggressive. A couple of times during the match I was a little bit defensive and she broke me.
"I told myself I had to take the match (into my own hands)."
Zheng is China's first US Open quarter-finalist since Wang Qiang in 2019. Two-time major champion Li Na reached the semi-finals in New York in 2013 and Peng Shuai did the same a year later.
Jabeur's latest quest for a maiden Grand Slam title fizzled out in an error-riddled display from a player whose US Open campaign has been disrupted by a flu virus.
The Tunisian lost the 2022 final to Iga Swiatek and has also finished runner-up at Wimbledon the past two years.
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