Kristie Ahn built on her impressive run at the US Open by beginning the Korea Open with a double-bagel victory on Monday.
Ahn claimed her first three grand slam match wins to reach the last 16 at Flushing Meadows, beating former major champions Svetlana Kuznetsova and Jelena Ostapenko before losing to Elise Mertens.
The 27-year-old climbed 48 places in the rankings as a result - from 141st to 93rd - breaching the top 100 for the first time in her career.
Making her first appearance since the final grand slam of the year, wildcard Ahn carried on in impressive fashion as she took apart Timea Bacsinszky 6-0 6-0 in Seoul.
The four seeds in action on Monday all advanced in straight sets, with Magda Linette (4) easing past 2015 champion Irina-Camelia Begu.
New Russian number one Ekaterina Alexandrova (2), compatriot Margarita Gasparyan (7) and Wang Yafan (8) avoided shocks, as Kristyna Pliskova and Ysaline Bonaventure also progressed.
There were upsets for the seeds at the Guangzhou Open, however, with Aleksandra Krunic - the 2017 finalist now world number 123 - beating 50th-ranked Aliaksandra Sasnovich (7).
Ons Jabeur (8) was also defeated, going down to Bernarda Pera in straight sets, while there were wins for veteran wildcard Sam Stosur, Viktorija Golubic and Marie Bouzkova.