Having climbed into the WTA's top 100, Kristie Ahn caught the eye again with a swift demolition of Timea Bacsinszky in Seoul.
Maria Sharapova and Naomi Osaka were notable winners at Flushing Meadows on Saturday as Angelique Kerber and Petra Kvitova suffered exits.
Two-time winner Serena Williams exited the Cincinnati Masters on Tuesday, as Caroline Garcia and Karolina Pliskova advanced.
Teenage American Caroline Dolehide was unable to shock Venus Williams at the Rogers Cup, where bad weather affected Maria Sharapova's match.
Two-time grand slam champion Svetlana Kuznetsova moved in to the next round of the Citi Open but Aleksandra Krunic fell at the first hurdle.
Aleksandra Krunic capitalised on a Kirsten Flipkens collapse to win her first WTA Tour title in style in Rosmalen.
Top seed and two-time champion Coco Vandeweghe failed to convert match point in defeat to Aleksandra Krunic.
Svetlana Kuznetsova progressed at the Istanbul Cup, but there was no such luck for Ekaterina Makarova.
Cramps claimed Garbine Muguruza in the humidity of the Brisbane International on Tuesday, before Johanna Konta overcame Ajla Tomljanovic.
Top seed Garbine Muguruza bowed out of the lead-up tournament when she was ahead 2-1 in the third set on Tuesday, citing cramps.