Russia's Svetlana Kuznetsova continued her poor run of form in the build up to the defence of her U.S. Open title, falling 6-4, 6-4 to Greece's Eleni Daniilidou in the second round of JP Morgan Chase Open on Wednesday.
While the second seed remained mired in worrying slump, her compatriots prospered, with number three Elena Dementieva easing past Australia's Samantha Stosur 6-4, 6-3 and fourth seed Nadia Petrova crushing American wild card Jill Craybas 6-3, 6-1.
Further down the Russian pecking order, 12th seed Dinara Safina overcame Japanese qualifier Rika Fujiwara 6-2, 7-5, while 16th seed Anna Chakvetadze outlasted Iveta Benesova 7-5, 4-6, 6-4.
Losing her opening match for the second consecutive week, Kuznetsova looked well short of the confidence that carried her to glory in New York.
The 22-year-old Daniilidou served well during the entire contest and matched Kuznetsova stroke-for-stroke in the rallies, securing victory with a booming ace down the middle.
"It's horrible," said Kuznetsova, who has not won a title in more than 10 months.
"I can't find my game. I don't have confidence and everything comes from the head. If I keep playing like this, I might as well go home."
Kim Clijsters enjoyed a happy return to the place where she gained the number one ranking two years ago with a 6-2, 6-1 drubbing of an erratic Karolina Sprem of Croatia.
"She likes to go for shots, but she doesn't have a Plan B," Clijsters said. "If she's on, she can hit incredible shots. If she's off, she struggles to change things and turn it around."
The fifth-seeded Clijsters has only lost one match on U.S. hard courts this year, that coming against China's Shuai Peng in San Diego last week.
Looking strong for a tilt at the U.S. Open starting on August 29, the 22-year-old Belgian has won hard court titles at Indian Wells, Miami and Stanford.
BIG MATCH
Chakvetadze's victory earned the world number 31 a third round encounter against compatriot and top seed Maria Sharapova, who is two wins away from taking over the number one ranking.
"I'll have to focus on every point," said Chakvetadze, who fell to Sharapova at the French Open.
"She's very good and it will be a big match for me."
Petrova, who suffered an elbow injury in San Diego last week, was briefly distracted by a spectator chatting on a mobile phone inside the stadium, but quickly regained her composure to dominate Craybas.
"It was quite annoying. I can almost tell you the number she was giving on the phone," the ninth-ranked Petrova said. "If I was more confident, I might have been more focused and it wouldn't have bothered me."
Earlier in the day, six seeded Frenchwoman Mary Pierce withdrew from the tournament with a right thigh strain.
Other seeded winners included number nine Daniela Hantuchova and number 13 Francesca Schiavone of Italy, while Spain's Conchita Martinez upset number 14 Gisela Dulko of Argentina 6-4, 6-2.
