The 595th-ranked Zhang Shuai added another chapter to her renaissance as she rolled into the quarter-finals of her home China Open on Tuesday to make more history.

Zhang's 6-4, 6-2 victory over Magdalena Frech was her fourth win in Beijing and all in straight sets, having come into the event after losing 24 singles matches in a row.

The barren run lasting more than 600 days was the second-longest on the WTA Tour in the Open Era, which began in 1968.

The 35-year-old Zhang, a former two-time Grand Slam quarter-finalist who has been plagued by injury, again made a nonsense of her ranking against the world number 31 Frech from Poland.

Zhang, a former top-25 player who has won two major doubles titles, will face Spain's 19th-ranked Paula Badosa in the last eight.

The lowest-ranked player to ever reach this stage of the China Open, Zhang raced away with the second set against Frech in front of a packed Beijing crowd on her country's national day.

She had two match points when serving at 5-1. Frech just about held on, but it was only a temporary reprieve.

Zhang struck a defiant pose immediately afterwards, standing still with her arms crossed and beaming.

Badosa dumped out US Open finalist Jessica Pegula in convincing fashion, 6-4, 6-0 to make the second-seeded American the biggest casualty so far. (AFP)