Moscow  - Former number one Jelena Jankovic Thursday completed the field for next week's year-end Sony Ericsson Championships as her last remaining rival dropped to a loss in Moscow.

Russian Vera Zvonareva joined Pole Agnieszka Radwanska in suffering defeats in the Russian capital, developments which allowed Jankovic through.

The event in Doha, Qatar, begins Tuesday with round-robin matches, ending with the November 1 final.

Jankovic completes an all-star line-up headed by Dinara Safina and Serena Williams. Other in the singles field: Elena Dementieva, Caroline Wozniacki, Svetlana Kuznetsova, Venus Williams and Victoria Azarenka.

"I'm really happy about making it for the third time in my career," said Jankovic, facing a second-round match in Moscow. "It's always a nice feeling to end the season playing in the Championships.

A year ago, the Serb went to the Gulf as world number one.

"Lot of nice things happened to me in a year, this season has been very tough for me. And not only on court - my mother got sick and operated, my grandmother died, I had problems with coaches, suffered with injuries in first half? I wasn't focus on tennis, that wasn't me on court."

After lifting two titles in 2008, the Jankovic won just two this season, in Marbella and Cincinnati.

She was one of three players on the WTA to hold the top ranking in 2009 along with Safina and Serena Williams.

Safina will return to number one in Monday's rankings, replacing Williams, who took over briefly in September.(dpa)