Radwanska through in Seoul
Top seed Agnieszka Radwanska began her KDB Korea Open campaign with a straightforward first-round victory over Alexandra Cadantu in Seoul.
The world number four came into the tournament on the back of a disappointing fourth-round exit from the US Open at the hands of Ekaterina Makarova.
Cadantu, world ranked 71, made a fight of it in the first set but Poland's Radwanska eased through the second set as her opponent's serve fell apart for a 6-4 6-0 victory in 77 minutes.
Second seed Maria Kirilenko went through 6-3 6-3 against Chin-wei Chan although the straight-sets win was not as simple as it appeared, the battle lasting an hour and 40 minutes.
However, there was a shock as fourth seed and world number 33 Klara Zakopalova tumbled out in straight sets against an opponent ranked 507 places below her.
Home favourite Su Jeong Jang was superior in all aspects of the match as she claimed a surprisingly easy 6-3 6-1 victory in just 64 minutes.
Andrea Petkovic was another seed to make way, although she battled for two hours seven minutes before going down 1-6 6-2 4-6 to Francesca Schiavone.
Eighth seed Annika Beck edged through 6-3 6-7 (5/7) 6-4 against Risa Osaki in a marathon match lasting two and three quarter hours.
Elsewhere, Irina-Camelia Begu beat Xinyun Han 6-3 6-4, Heather Watson was downed 3-6 6-3 4-6 by Kimiko Date-Krumm and Ons Jabeur enjoyed a 7-5 6-0 win over Nastassja Burnett.