BANGKOK (AFP) Defending champion Vera Zvonareva heads the field at the 220,000-dollar Pattaya Open this week and the Russian appears to have a comfortable draw as she bids to win her ninth career title. Fifth seed and 2007 champion Sybille Bammer of Austria will be the first seeded hurdle she will have to overcome, in the quarter-finals, and fourth seed Yaroslava Shvedova could be her semi-final opponent. Coming into the tournament last year ranked five, Zvonareva has now slipped to 14 after suffering a right ankle injury which eventually required surgery to remove scar tissue. Having had to withdraw before her second match at the WTA Championships in November, she also had to retire in the first set against Elena Vesnina in Sydney with the same injury before recovering to reach the fourth round of the Australian Open. Germanys rising star Sabine Lisicki is seeded two and will be seeking to kick start her season after disappointing results in Australia. She fell to Victoria Azarenka in her opening round in Sydney and then, ranked 24, she was upset in the second round of the Australian Open by 73rd-ranked Italian Alberta Brianti. Her first real challenge could come from the resilient seventh seed Kimiko Date Krumm of Japan, who last year entered the history books by becoming the second oldest player to win a Tour singles title a day before her 39th birthday. Should Lisicki advance to the semi-finals her likely opponent would be third seeded Russian Vera Dushevina. While Lisicki has struggled for a few weeks, Anna Chakvetadze will be trying to reverse a career decline that has seen her slump from a career-high of five in the world in 2007 to 74 this week. This year she was beaten by Date Krumm in the first round in Auckland, failed to survive the qualifying rounds in Hobart and then was beaten in the first round of the Australian Open by Flavia Pennetta. Date Krumms age means there is a vast gap between the youngest and oldest players in the 32-player field, with the youngest competitor coming from Thailand in the form of 18-year old Wimbledon junior champion Noppawan Lertcheewakarn. The Pattaya Open is part of the WTA Tours Road To Bali, comprising of 32 International Series tournaments held throughout the year. The players who earn most points at those tournaments throughout the season qualify for the 600,000-dollar Championships to be held at the Bali International Convention Centre, Nusa Dua, between November 4-7. Seeds: 1. Vera Zvonareva (RUS) 2. Sabine Lisicki (GER) 3. Vera Dushevina (RUS) 4. Yaroslava Shvedova (KAZ) 5. Sybille Bammer (AUT) 6. Sania Mirza (IND) 7. Kimiko Date Krumm (JPN) 8. Julia Georges (GER)