Seoul - Richel Hogenkamp beat big-hitting Czech Denisa Allertova 6-4, 6-4 on Wednesday to reach the Korea Open quarter-finals, as she fights to return to the top 100.
It is the first time the Dutch 25-year-old has reached a quarter-final on hardcourts and afterwards said she had been focused on keeping her opponent guessing.
"She likes a strike zone at about hip level, so by mixing it up, I was able to get her to make some more mistakes. I think it was a good tactic," said Hogenkamp, who is ranked 119.
She will now face either fellow Dutch player Arantxa Rus or Australia's Priscilla Hon for a spot in the final four.
Elsewhere Thai Luksika Kumkhum won a 6-3, 6-3 win over Ekaterina Alexandrova and will next play No 4 seed Sorana Cirstea or surging American Nicole Gibbs.
Results from the third day of the Korea Open WTA tournament on Wednesday (x denotes seeding):
Luksika Kumkhum (THA) bt Ekaterina Alexandrova (RUS) 6-3, 6-3
Beatriz Haddad Maia (BRA) bt Irina Begu (ROM x5) 6-3, 4-6, 6-2
Sara Sorribes Tormo (ESP) bt Na-Lae Han (KOR) 6-1, 6-2
Richel Hogenkamp (NED) bt Denisa Allertova (CZE) 6-4, 6-4
Kristie Ahn (USA) bt Tatjana Maria (GER x6) 7-5, 7-5