The Swiss Marlen Reusser (SD Worx), an experienced rider, broke company with the peloton of the favorites 20 km from the finish.
The time trial specialist swallowed the last portion of the Champagne white paths without weakening during the 4th stage of the Women's Tour with Swift Troyes-Bar-sur-Aube.
She was ahead of the French Evita Muzic (at 1'24''), the Belarusian Alena Amialiusik and the American Veronica Ewers.
The Dutch Marianne Vos, yellow jersey, at the head of the pack of favorites, taking 5th place.
In the general classification, Marianne Vos is ahead of the Italian Silvia Persico (16'') and the Polish Katarzyna Niewiadoma (16'').
The first Frenchwoman, Juliette Labous is 7th at 1'5''.
Marlen Reusser AFP