Birrell storms into quarters of WTA event in Seoul

After winning her opening-round match in straight sets by defeating American Sachia Vickery, Birrell took little time in claiming the opening eight games of her second-round contest in Seoul.

The current world No.102, who has a career-best ranking of 100, broke again in the fifth and seventh games of the second set to wrap up one of her most convincing victories on tour.

Elsewhere, fourth seed Marie Bouzkova was leading 6-0 1-0 when her German opponent Eva Lys retired with injury. The Czech will now face China's Yue Yuan in the quarters.

Top seed and world No.4 Jessica Pegula is in action later on Thursday, taking on fellow American Ashlyn Krueger with compatriot Claire Liu awaiting the victor.