Radwanska, making her debut in Seoul tournament, will next face against Vera Dushevina.
Japanese veteran Kimiko Date-Krumm upset second-seeded Maria Kirilenko 6-3, 6-1 and will face Francesca Schiavone in the quarters.
Wild-card entry Jang Su-jeong also advanced with a 1-6, 6-4, 6-1 win over qualifier Ons Jabeur. Jang faces Lara Arruabarrena in the last eight.
Copyright 2013 The Associated
Press. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.