Maria Sharapova became the latest seed to exit the Wuhan Open as she was beaten in straight sets by qualifier Timea Bacsinszky.
Sharapova, the fourth seed at the WTA Premier hard-court event, followed Simona Halep and Agnieszka Radwanska out of the competition as Bacsinszky recorded the biggest win of her career on Wednesday.
The 25-year-old had only previously defeated a player in the world top 10 due to retirements, but showed no nerves to beat five-time grand slam champion Sharapova 7-6 (7-3) 7-5.
Bacsinszky edged a tight opening set by claiming three mini breaks in the tie-break, but Sharapova hit back by breaking immediately in the second set.
However, Bacsinszky's fighting spirit brought her back into the match, as she won four of the last five games to set up a quarter-final clash with Caroline Wozniacki, who eased past Casey Dellacqua 6-0 6-3.
Sharapova's elimination means only four seeds remain in the competition, with third seed Petra Kvitova battling past Karolina Pliskova 6-3 2-6 6-4 to set up a match with Caroline Garcia, who earlier beat Coco Vandeweghe 6-3 6-2.
Eugenie Bouchard is also be in the next round after she beat Alison Riske 6-2 6-3 in 78 minutes to reach her first quarter-final since Wimbledon.
Bouchard will meet Alize Cornet after her 7-6 (7-4) 1-6 6-3 win over Kirsten Flipkens, while the final seed in the draw, Angelique Kerber, also progressed with a comfortable 6-1 6-1 victory against Barbora Zahlavova-Strycova.
The German will face Elina Svitolina in the next round after she was given a walkover win as Garbine Muguruza was forced to withdraw due to gastroenteritis.