Stosur rolls in TOC opener

Sofia, Bulgaria ( - Former U.S. Open champion Sam Stosur was an easy round-robin winner Wednesday at the season-ending WTA Tournament of Champions.

The fourth-seeded Stosur drubbed fifth-seeded Russian Elena Vesnina 6-3, 6-3 on the indoor hardcourt at Armeets Arena.

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.

Group Sredets is comprised of second-seeded and two-time Tournament of Champions winner Ana Ivanovic (1-0), Stosur (1-0), Vesnina (0-1) and eighth- seeded Tsvetana Pironkova (0-1).

Group Serdika features top-seeded Simona Halep (1-0), third-seeded Russian Maria Kirilenko (0-1), sixth-seeded Russian Anastasia Pavlyuchenkova (0-1) and seventh-seeded Frenchwoman Alize Cornet (1-0). An injured Kirilenko has been replaced in the field by Russian alternate Elina Svitolina.

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.