ST. PETERSBURG, Russia – Venus Williams lost her first match since the Australian Open to Kristina Mladenovic 6-3, 6-1 in the St. Petersburg Ladies Trophy on Thursday.

Seeded fourth, Williams showed none of the spark which took her to the Australian Open final last weekend, failing to record a single winner in the opening set compared to 15 for her French opponent.

Mladenovic broke the tired-looking Williams in the first game of the second set and swiftly wrapped up the second-round win. Williams received a bye in the first round.

In the quarterfinals, Mladenovic meets defending St. Petersburg champion Roberta Vinci, who beat Andrea Petkovic 6-4, 6-4. Vinci, the sixth-seeded Italian, was broken twice in the first set.

Also, second-seeded Dominika Cibulkova of Slovakia cruised past Donna Vekic of Croatia 6-2, 6-2 and into the quarterfinals. Cibulkova will play fifth-seeded Russian Elena Vesnina, who progressed by defeating France’s Alize Cornet 2-6, 6-3, 6-3.