Petra Kvitova got her season finale debut of to a winning start with a straight-sets victory over Vera Zvonareva in Istanbul.
Czech Republic's Kvitova has been tipped by many to win the title this week and she lived up to that billing by only allowing her opponent to hold her serve twice throughout the match.
Kvitova claimed the first set with relative ease, breaking early in the contest before going on to record a 6-2 success.
The second set appeared to be mirroring the first, until Zvonareva broke in the sixth game to bring the score back to 4-4.
However, it proved to be a momentary blip for 21-year-old Kvitova, who went on to win 6-2 6-4.
The other match in the Red Group between Caroline Wozniacki and Agnieszka Radwanska is due to get underway shortly.