Sofia, Bulgaria (SportsNetwork.com) - Top-seeded Simona Halep and two-time champion Ana Ivanovic were both opening-day winners at the WTA Tournament of Champions.
Halep posted a 6-3, 6-3 victory over sixth-seeded Russian Anastasia Pavlyuchenkova on the indoor hardcourt at Armeec Arena. The second-seeded Ivanovic breezed past No. 8 seed Bulgarian Tsvetana Pironkova 6-0, 6-2 in her first match.
This event, in its fifth year, features an eight-woman field that is divided into two groups. Round-robin play is staged Tuesday through Friday, with the semifinals on Saturday and a Sunday final.
Ivanovic, the 2010 and 2011 titlist, and Pironkova make up half of Group Sredets. They are joined by fourth-seeded Australian Samantha Stosur and fifth-seeded Russian Elena Vesnina.
Group Serdika includes Halep, third-seeded Russian Maria Kirilenko, Pavlyuchenkova and seventh-seeded Frenchwoman Alize Cornet.
Cornet was ahead 5-0 in the first set against Kirilenko before the latter retired.
The field consists of the six highest-ranked players who won at least one International Series tournament during the year and did not qualify for last week's WTA Championships in Istanbul or are not participating in this week's Fed Cup final. Two wild cards - Ivanovic and Pironkova - were included as well.
Russian Nadia Petrova defeated Dane Caroline Wozniacki to win the title last year in Sofia's debut as host. The tournament was previously held in Bali.