It was a windy, miserable day in the Paris suburb of Yvelines, and FDJ used that fact to its full potential, splitting the race into several small pelotons on the first of the two Bois-d'Arcy circuits. This, on a stage largely expected to be a boring sprinters' day, changed the face of this year's race, and caused all but two of the GC favourites to lose time. Of the GC men, only Daniel Martin, Ion Izagirre and Sergio Henao made the original split. Martin was the one most advantaged by this, having five Quickstep teammates in the group, including sprinter Marcel Kittel and wildcard Julian Alaphilippe.
Alberto Contador, Ilnur Zakarin, Richie Porte, Romain Bardet, Simon Yates and other GC favourites, as well as sprinters Nacer Bouhanni, Magnus Cort, Dylan Groenewegen, Sam Bennett and Dan McLay all missed out early on, and spent a miserable afternoon in the second peloton, taking part and forming passengers in a sporadic chase led by Trek (largely in the form of Jarlinson Pantano), BMC and Orica.
Coming into the finish, back in Bois-D'Arcy, the effort of the day began to take its toll on the men in the lead group, as Bryan Coquard, André Greipel and Marcel Kittel were dropped, along with would-be post-stage GC favourite Ion Izagirre all fell behind in the closing kilometres, and as the road began to ramp up in the penultimate kilometres, it became clear who the day's strongest men were. Julian Alaphilippe, realising he was by this stage his team's best hope of a win, jumped away from the lead group just before the flamme rouge. Nobody bar Arnaud Démare was willing or able to follow him. Démare was not only willing to follow, but able to catch and willing to work, going past his more diminutive compatriot and leading the duo into the final few metres. Alaphilippe kicked off the sprint, briefly gaining a couple of metres, but he was never going to match the power of the FDJ man, who powered to victory and the leader's yellow jersey.
Behind, the stragglers straggled. Alexander Kristoff won the sprint for third over Philippe Gilbert, but it may be the men in sixth and ninth place who are happiest with their day's work. Dan Martin and Sergio Henao were by far the best of the climbers, and if nothing else they now have a substantial enough buffer over their rivals to see them through the stage four time-trial in touch with the other GC riders. Those riders came in thusly: Romain Bardet, who crashed in the latter kilometres but came back strongly (Update: Obviously breaking the rules to do so. He was disqualified for holding onto a team car soon after crossing the line), came in at 0:47 with Richie Porte and Ilnur Zakarin. Alberto Contador, Ion Izagirre and Simon Yates also came in together, 1:04 behind Démare.
That gives you a classification of GC contenders that looks something like this:
2. Martin, at 0:15
3. Henao, at 0:15
4. Porte, at 0:53
5. Bardet, at 0:53 (Update: Bardet was disqualified)
5. Zakarin, at 0:53
6. Contador, at 1:10
7. Izagirre, at 1:10
8. Yates, at 1:10
9. Kruijswijk, at 2:34
That's essentially all of the climbers left in the race anyway. The rest finished in the peloton, sixteen minutes behind.