The 67.5 km stage to the top of the Col d'Izoard was a consistently hard and tough affair right from the dropping of the flag to the finish. A fast start nullified a number of attacks at the start of the race, a group of five gaining a short-lived advantage before being brought back.
Former world champion time-triallist Linda Villumsen (VeloConcept) went on a long-range attack on the flat sections that led into the imposing climb of the Col d'Izoard. Villumsen was given a short leash, with the peloton well aware of her strength and capping her gap at just under a minute.
As the peloton hit the lower slopes of the Col, Boels-Dolmans went to the front and set a hard pace. With nine kilometres remaining Lizzie Deignan (Boels-Dolmans) took up the pace-setting, the hard pace dropping all but the best climbers, including some of her teammates.
She relented briefly and there was a quick regrouping before the final kilometres, where the climb's hardest gradients began to kick in. Deignan moved back to the front and began dropping riders again in earnest. Hanging in the front group were van Vleuten, Shara Gillow (FDJ), Amanda Spratt (Orica-Scott), Elisa Longo Borghini (Wiggle-High5) and Megan Guanier (Boels-Dolmans).
Van Vleuten launched a big attack from just over four kilometres out, on some of the steepest gradients the race had to offer. She immediately got a gap and set to the task of increasing it all the way to the finish. Deignan drove the chase behind with Gilow hanging gamely in her wheel.
With 2.5km left in the climb, van Vleuten navigated a small descent before her chain appeared to slip, bring the Dutch star to a near stand-still on the road. She was able to recover however and continued to power her way into the finish.
Behind her, the race had split into single riders coming up the mountain as Gillow cracked and began to slip back the course.
In the end, van Vleuten conquered her misbehaving bike to take the win by 43 seconds from Deignan, with Longo Borghini a further 40 seconds back in third.
After the stage, an exhausted van Vleuten was struggling to describe her emotions on taking the victory.
"To finish here at the Tour de France in front of so many people, it's amazing," said van Vleuten. "Especially as before I wasn't a climber, the Rio Olympics was the first time I could really climb uphill and now for them to organise this uphill finish at the Tour de France, that's great."
Van Vleuten's attack from over four kilometres out raised some eyebrows with still so much hard climbing remaining on the stage.
"I have to admit, I regretted it a bit that I went so early! There's sort of double tactics in my mind as we have the pursuit on Saturday, so it's better if you save something for the time trial as well. Everyone is hurting at the moment, so maybe it is better to go. If you wait too long it makes it too easy for the other girls, if I have the legs I can test the legs and it's good to go early."
The top 20 riders will go on to compete in the pursuit format on Saturday, with van Vleuten to start the race first and be chased by riders behind.