Titleholder Aravane Rezai, still struggling to recapture her glittering form from earlier in the year, suffered a heavy 6-1 6-2 loss to Russia`s Alisa Kleybanova in the quarter-finals of the Tournament of Champions on Friday.
Kleybanova now faces Daniela Hantuchova in the semis after the Slovak defeated Belgium`s Yanina Wickmayer 6-4 7-6.
Rezai`s scoreline suggested an overwhelming victory by Kleybanova, but most of the games were closely contested.
The defending champion and number two seed was playing her first match of the tournament but managed to convert just one of eight break points. The powerful Kleybanova won six of nine.
The Frenchwoman`s defeat was not unexpected.
After winning a major title in Madrid by beating Justine Henin, Jelena Jankovic and Venus Williams, and then qualifying for the Tournament of Champions by winning the Swedish Open shortly after Wimbledon, her career has since stalled.
She had failed to win back-to-back matches in her previous eight tournaments and her loss to Kleybanova was her fifth opening round defeat in nine events.
Rezai blamed a lack of confidence, the result of her being distracted by her brother`s recent illness.
She told reporters: "I`m a little bit down in my confidence because I lost a lot of matches during the end of the season. I didn`t play well today at the important points and that`s why the score is like this."
The 23-year-old plans to return home and immediately begin working on her game for next season with an ambition of reaching the top 10 in 2011.
Hantuchova, runner-up to Lindsay Davenport in 2007, got the best of an untidy match with Wickmayer who complained about spectator noise and several times smashed her racquet to the ground.
The Slovak served for victory at 5-4 but dropped her serve to love before clinching the tiebreak when her opponent struck her eighth double-fault.