Fast-Step Flooring rider Alaphilippe crossed the road to an exuberant reception from the French followers on the finish of a stage the place the principle race contenders held fire.
But final 12 months’s runner-up Rigoberto Uran misplaced time as he struggled on the final climb.
Belgium’s Greg van Avermaet was a part of the breakaway group with Alaphilippe and completed fourth to keep up his grip on the yellow jersey.
Spain’s Ion Izagirre and Estonian Rein Taaramae completed second and third, respectively.
“I did not expect this, it’s incredible,” stated the 26-year-old Alaphilippe after his first win on the Tour.
“I think I timed my effort perfectly I’m improving. I managed to keep control of my emotions. Maybe two years ago I would have attacked too early.”
Colombian Uran, who suffered a crash on the cobbles in Sunday’s ninth stage, completed two minutes 29 seconds behind the group of important contenders as his podium hopes just about vanished within the first Alpine stage.
Alaphilippe, one in all France’s hottest prospects, went solo within the col de la Colombiere, the final of 5 categorised climbs, and by no means seemed again. He elevated his lead within the closing descent to grab the polka dot jersey for the mountains classification.
A one-day basic specialist who received the distinguished Fleche Wallonne final Spring, Alaphilippe introduced his group their 50th win of the season.
World champion Peter Sagan was additionally a part of the day’s breakaway group and elevated his lead within the factors classification as he seeks a record-equalling sixth inexperienced jersey.
A day after the primary relaxation day, the large guns had been in no temper to take dangers forward of two extra phases within the Alps.
Defending champion Chris Froome’s Crew Sky managed the tempo and prevented assaults as headwinds blew within the ascent of the col de la Colombiere.
Solely Eire’s Dan Martin tried his luck contained in the final kilometre of the climb, however he was shortly reined in on a disappointing day for followers, who had been anticipating fireworks.
They may come on Wednesday’s 11th stage, a brutal 108.5-km mountain trek from Albertville to La Rosiere that options 4 categorised climbs, together with a summit end.
(Reporting by Julien Pretot; Modifying by Toby Davis)