Former world number one Ana Ivanovic was thrashed 6-0 6-0 by Italian Roberta Vinci in the second round of the WTA Rogers Cup in Montreal on Thursday.
Vinci needed only 44 minutes to eliminate the 11th-seeded Serbian, who won this event six years ago but admitted she never got going against the world number 28.
"I really struggled to find my rhythm out there," Ivanovic said on www.wtatennis.com. "It came as a surprise a little bit because I was practising really well.
"I was struggling to find my feet and get two consecutive balls in the court. Against players like Roberta, who don't make many errors, it's always going to be tough to win like that.
"When you're down 4-0, 5-0, 6-0, the panic starts to set in. I forced a little bit. It was bad already without that. It was really, really tough for me out there."
Ivanovic's compatriot Jelena Jankovic - seeded 13th - did not fare much better, picking up only five games as Canada's Aleksandra Wozniak advanced with a 6-2 6-3 win.
Twelfth-seeded Slovakian Dominika Cibulkova was also ousted, going down 6-4 6-4 to American Varvara Lepchenko, while Carla Suarez-Navarro overcame 15th seed Sabine Lisicki of Germany 3-6 6-3 6-4.
Agnieszka Radwanska, the second seed from Poland, looked in danger of joining the seeded casualties after losing the first set against Germany's Mona Barthel but fought back to prevail 4-6 6-3 7-6 (7/5).
Ninth-seeded Frenchwoman Marion Bartoli and Li Na, the 10th seed from China, enjoyed smooth passages into the last 16, though, with straight-sets wins over China's Peng Shuai and Canadian wild card Eugenie Bouchard, respectively.
American Christina McHale also progressed thanks to a 7-5 3-6 6-2 triumph over Kazakhstan's Galina Voskoboeva.
The matches between top seed Victoria Azarenka and Tamira Paszek, Angelique Kerber and Ekaterina Makarova, and Kiki Bertens and Caroline Wozniacki, were suspended due to rain.