Beijing - Top seed and world number three Simona Halep, along with second seed Petra Kvitova, ranked four, both breezed past lowly opponents in straight sets on Thursday to reach the semi-finals of the WTA Shenzhen Open.
Romanian Halep, last year's French Open runner-up, made short work of Serbian qualifier Aleksandra Krunic, winning through 6-3, 6-3 in 62 minutes.
Double Wimbledon winner Kvitova needed slightly longer to dispose of her fellow Czech Tereza Smitkova but did so 7-5, 6-4.
She will play Swiss number eight seed Timea Bacsinszky in the semi-finals, after former world number two Vera Zvonareva's injury devils returned to haunt her and she retired in tears just 29 minutes into her first WTA quarter-final since 2012.
The Russian reached the Wimbledon and US Open finals in 2010 but has since been plagued by injury and illness, dropping to 250 in the world, and was attempting to launch a 2015 comeback at the $500 000 tournament.
Zvonareva was already 3-2 down after 47th-ranked Bacsinszky, her doubles partner, broke her serve.
Halep's semi-final opponent will be home player Zheng Saisai, 20, who is ranked 97th but beat fourth seed Zarina Diyas of Kazakhstan 3-6, 7-6, 6-2 to maintain Chinese interest in the event.
Results from the fifth day of the WTA Shenzhen Open in Shenzhen on Thursday (x denotes seeding):
Timea Bacsinszky (SUI x8) bt Vera Zvonareva (RUS) 3-2 (rtd)
Zheng Saisai (CHN) bt Zarina Diyas (KAZ x4) 3-6, 7-6 (7/2), 6-2
Simona Halep (ROU x1) bt Aleksandra Krunic (SRB) 6-3, 6-3
Petra Kvitova (CZE x2) bt Tereza Smitkova (CZE) 7-5, 6-4