Sixth seed Angelique Kerber has suffered a shock defeat at the hands of Roberta Vinci in the third round of the Rogers Cup in Montreal.
The Italian, who had lost her one previous match against Kerber, broke the German twice to take the opening set 6-2.
With both players dropping serve twice in the second, the world number 28 won the match with a 9-7 triumph in the tie-break.
Vinci's opponent in the quarter-finals will be Lucie Safarova following the Czech's surprise win over Sam Stosur on Friday.