Former world number one Caroline Wozniacki moved to the brink of a semi-final place at the Qatar Airways Tournament of Champions in Sofia following a comfortable win over Roberta Vinci.
Wozniacki was largely untroubled as she posted a 6-3 6-1 win, recording her second victory in as many games to start the round-robin format.
The Dane, now ranked No.11 in the world, only dropped four games in her opening win against Hsieh Su-wei on Tuesday.
In the other group, Nadia Petrova and Maria Kirilenko both grabbed straight-set wins in their opening matches.
Second seed Petrova was too powerful for Zheng Jie, triumphing 6-3 6-3, while fellow Russian Kirilenko swept aside local hopeful Tsvetana Pironkova - who beat Zheng - 6-1 6-4.