Third seed Marlene Weingartner of Germany made an early exit at the Korea Open as she crashed out to Poland's Marta Domachowska in the first round.
Domachowska beat Weingartner, who was runner-up to Svetlana Kuznetsova in Bali two weeks ago, 6-1 6-3.
Fourth seed Mashona Washington of the USA also made a surprise exit, with Catalina Castano getting the better of her 5-7 6-4 6-4.
Eighth seed Samantha Stosur beat Yoon Jeong Cho 7-6 (7-1) 6-4.
Wimbledon champion and top seed Maria Sharapova is expected to play on Tuesday.