Romanian Sorana Cirstea (33) reached the quarter-finals of a Grand Slam for the first time in 14 years on Sunday after upsetting 15th seed Belinda Bencic (26) 6-3, 6-3 at the US Open.
Making her 59th Grand Slam main draw appearance and 15th at the US Open, the Romanian's only other quarter-final appearance was at the 2009 French Open.
Cirstea becomes the oldest woman to reach the last eight at the US Open for the first time.
The upset is just the latest in what has been a remarkable run for the Cirstea, who had already delivered one of the big Flushing Meadows shocks taking out fourth seed and 2022 Wimbledon champion Elena Rybakina (24) in the third.
Next up for the Romanian is Czech 10th seed Karolina Muchova (27) who advanced with a 6-3, 5-7, 6-1 win over China's Wang Xinyu (22).
