Ricarda Bauernfeind holds off pack to win women's Tour de France stage five
"It's fantastic. Wow!" the German told Eurosport at the finish, after becoming the youngest stage winner in the two-year history of the event.
In her first season at the elite professional level, she broke away on a short climb with 36km to go and then held on as the main contenders in the chasing pack waited for others to lead the pursuit.
Bauernfeind finished 22 seconds ahead of Swiss rider Marlen Reusser and compatriot Liane Lippert. Leader Belgian Kopecky was fourth, another 10 seconds back, at the head of the pack.
Demi Vollering fell from second to seventh, penalised 20 seconds for drafting behind the team car after dropping back from the peloton early in the stage. She slipped 12sec behind her great Dutch rival Annemiek van Vleuten, who is fifth.
South African Ashleigh Moolman jumped to second, 49sec behind Kopecky.
Bauernfeind, just 1.66m (5-foot-4) tall, also gave her Canyon team a first big win after they had hunted down an early breakaway.
"An incredible team ride we had to chase the first group because I missed it," she said.
"Then it was up to me and I tried to attack and it worked out."
The day after the longest stage of the race, several riders dropped out.
Dutch sprinter Lorena Wiebes, the winner of stage three on Tuesday, was unable to start stage five complaining of digestive problems.
Swede Jenny Rissveds and Norwegian Mie Bjorndal Ottestad, both victims of crashes the day before, also did not start.
French rider Evita Muzic, eighth overall last year and 14th this time, gave up after just a few kilometres with stomach pains. Canadian Gabrielle Pilote-Fortin also withdrew.
On Friday, the peloton will travel from Albi to Blagnac on a largely flat 122km route that should favour the sprinters.