Thibaut Pinot (Groupama FDJ) also took 20 seconds out of the GC candidates after breaking clear with his compatriot, while Geraint Thomas survived a crash with 16km to go and managed to get back into the bunch.
It was a sensational ride by De Gendt (Lotto Soudal), who richly deserved his stage win after holding off the chasing French pair. But Alaphilippe won’t mind too much after claiming back the yellow jersey from Giulio Ciccone. De Gendt's return to winning ways proved once again he’s the true king of the breakaway.
'He timed it beautifully!' - De Gendt clinches Stage 8 win
With a course that seemed tailor-made for an escape success, we expected to see a huge battle to get into the move, but in the end the quartet managed to get free without much hassle. Niki Terpstra (Total Direct Energie), Alessandro De Marchi (CCC Team) and Ben King (Dimension Data) were the riders who joined De Gendt in the wattage factory. It was the final climb when De Gendt went solo, after he and De Marchi had ditched the other two on the Cote de la Croix de Part some 50 kilometres earlier, with De Gendt later heaping praise on his breakaway partner, saying: "He's the kind of guy who rides with full commitment. It was a shame he didn't have the legs in the end. It would have been nice to sprint against him for the win."
De Gendt: I had a really good feeling all day
A Frenchman in yellow on Bastille Day
While Alaphilippe and Pinot will be a little disappointed to have fallen just a couple of hundred metres short of winning the stage, both will find much to console them. Pinot leaps from seventh to third on the general classification, leapfrogging both Egan Bernal and Geraint Thomas of Team Ineos, after gaining 19 seconds through time bonifications for his second place finish and the day's last KOM, plus the eventual countback.
Alaphilippe will be doubly delighted to regain the maillot jaune after losing it to Giulio Ciccone two days ago. The Deceuninck - Quick Step rider will wear the yellow jersey tomorrow on Bastille Day, the first home rider to do so since Thomas Voeckler in 2011.
Thomas survives crash unscathed
It was a day more eventful than Geraint Thomas might've hoped. The Welshman was dropped at the halfway point of the stage after an untimely puncture, only to be paced back onto the bunch in good time by his fellow Welshman Luke Rowe. Then with 16km of the stage remaining he was unable to get out of the way of a crash caused by his team mate Gianni Moscon coming into contact with Michael Woods (EF Education First). Moscon's bike was busted into two piece by the impact.
Luckily for the reigning champion, Thomas had plenty of domestiques who still had functioning bikes to pace him back to the bunch once again, where he rejoined Egan Bernal in the front ten riders by the time they crossed the line. Thomas was not the only rider to hit the deck, after breakaway rider De Marchi overshot a corner going downhill and almost ended up in a country yard.
De Marchi makes wrong turn on descent, nearly clatters into barrier
Peter Sagan extended his advantage in the points classification by picking up some points at the day's intermediate sprint. He followed that up with a respectable fifth place behind Michael Matthews in the field sprint after being dropped on the third-from-last climb. Matthews gained one place in the classification at the expense of Sonny Colbrelli who couldn't hack the pace in the finale.
As with previous years, it looks like only a major mishap or an hors delai time-out stands between Sagan and a seventh green jersey victory.
A look ahead
Tomorrow it's another bumpy ride, with a mere three categorised climbs on the 171 kilometres between St Etienne and Brioude. Without wishing to sound like the Tour is a broken record, you'd be well advised to stick a quid on either Thomas De Gendt or Julian Alaphilippe.