Updated

Former world No. 1 Caroline Wozniacki highlighted Wednesday's round-robin winners at the $750,000 Tournament of Champions.

The top-seeded Danish star moved to 2-0 for the week with a 6-3, 6-1 handling of fourth-seeded Italian Roberta Vinci (1-1) in 68 minutes on the indoor hardcourts at Armeets Arena.

Wozniacki will play her final round-robin match of the week on Thursday against seventh-seeded Slovakian veteran Daniela Hantuchova (0-1).

Also on Wednesday in Sofia, second-seeded Russian Nadia Petrova (1-0) opened her week with a 6-3, 6-3 victory over sixth-seeded Chinese Zheng Jie (0-2) and third-seeded Russian Maria Kirilenko (1-0) topped eighth-seeded Bulgarian crowd favorite Tsvetana Pironkova 6-1, 6-4.

Thursday's other round-robin affairs will pit Petrova against her compatriot Kirilenko and Vinci versus fifth-seeded Su-Wei Hsieh of Taipei.

The Tournament of Champions is the finale for the WTA's International Series, with the six highest-ranked players who have won an International title this year -- and two wild cards -- comprising the eight-woman field. The four- player Serdika Group boasts Wozniacki, Vinci, Hsieh (0-1) and Hantuchova, while the four-player Sredets Group features Petrova, Kirilenko, Zheng and Pironkova (1-1).

The tournament format sees two round-robin groups play out over the first four days, with the semifinals on Saturday and the final on Sunday.