Top seed Zhang Shuai advanced to the semi-finals of the WTA Hawaii Open on Friday, but Sabine Lisicki succumbed to injury.
Zhang got the better of Samantha Crawford in straight sets, in a battle of two seeds in Honolulu.
Looking to win her second WTA title at the 125k event, Zhang defeated the eighth-seeded American 6-4 6-4.
Awaiting Zhang in the final four is sixth seed Evgeniya Rodina.
Rodina outlasted Sachia Vickery 6-3 3-6 6-4 after almost two hours on court in their quarter-final clash.
Lisicki, meanwhile, retired in her match against Jacqueline Cako.
The German took the first set 6-3 but then dropped the second before calling it quits when 2-0 down in the decider.
Cako will now face fourth seed CiCi Bellis, who eased past Sara Sorribes Tormo 6-1 6-1.