Edvald Boasson Hagen has won his first Tour de France stage since 2011 in a strong finish.
It was a roundabout 2km out that proved decisive as a breakaway group of 20 attacked the finish.
The eventual winner decided to go right round the roundabout rather than left, it proved to be shorter and gave him just the platform he needed to launch his stage winning attack.
has held off a strong challenge to win stage 18 of the Tour de France.
Chris Froome once again performed well, finishing fourth and retaining the yellow jersey. Romain Bardet beat him on the line to third place and the bonus six seconds.
Lizzie Deignan has finished second behind Dutch rider Annemiek van Vleuten on stage one of the two-day La Course.
The race concludes on Saturday with a chase in Marseille where riders will set off according to the time gaps established on today's stage.
Stage One result:
1. Annemiek Van Vleuten (Orica-Scott) 2hrs 7mins 18secs
2. Lizzie Deignan (Boels Dolmans Cyclingteam) +43secs
3. Elisa Longo Borghini (Wiggle Highs) +1min 23secs
4. Megan Guarnier (Boels Dolmans Cyclingteam) +1min 28secs
5. Shara Gillow (FDJ Nouvelle-Aquitaine Futuroscope) +1min 33secs
The riders climb this morning to the highest point of the race, 2,642m at the top of Galivier before descending towards the finish.
We could be in for a few spills as thunderstorms are scheduled for this afternoon.
Michael Matthews will be looking to win his third stage in four days in this stunning scenery.