Seoul - Top-seeded Jelena Ostapenko beat Lara Arruabarrena 6-3, 6-3 to advance to the second round of the Korea Open on Wednesday.
Ostapenko, the 2017 French Open champion, broke her opponent five times while notching up 32 winners to 29 unforced errors.
"She's a very good player and very consistent," Ostapenko said. "Today was a good match for me, especially for the first round because first rounds are always tough."
Also, second-seeded Kiki Bertens beat Luksika Kumkhum 7-6 (7), 6-2.
Sixth-seeded Hsieh Su-wei defeated Stefanie Voegele 6-2, 6-1, and Evgeniya Rodina outlasted No 8 Kirsten Flipkens 6-4, 4-6, 7-5.
At Guangzhou, China, fifth-seeded Yulia Putintseva defeated Sabine Lisicke 6-3, 6-3 to reach the quarter-finals of the Guangzhou Open. Also, seventh-seeded Vera Lapko overpowered Deniz Khazaniuk 6-2, 7-5.