Along with Astana's Jakob Fuglsang and EF Education First's Rigoberto Uran, the Tasmanian and Pinot were the two biggest GC favourites caught napping when a number of teams capitalised on the crosswinds in the final 30 kilometres of the stage.
Geraint Thomas, Egan Bernal, Nairo Quintana, and Steven Kruijswijk all made the front group and finished in the reduced front bunch, one minute and 40 seconds ahead of Pinot and Porte. Despite EF Education First initiating the fireworks with Sunweb and then Ineos, they too fell back behind, Uran finishing with Porte and Pinot.
The finishing gap sees Porte now three minutes and 59 seconds behind the race leader Julian Alaphilippe (Deceuninck-QuickStep) and two minutes and 47 seconds behind the leading general classification candidate Geraint Thomas (Team Ineos).
Not even the reduced bunch sprint unfolded according to the transition stage script. Belgian cyclocross wunderkind capitalised on his background to back up sustained efforts in the crosswinds and out-kick fastmen Elia Viviani (Deceuninck-QuickStep), Caleb Ewan (Soudal Lotto), Michael Matthews (Team Sunweb) over the line.
With Dylan Groenewegen also missing the split but GC leader Kruijswijk safely tucked away up front, Jumbo Visma and the Tour debutant were more than happy with how the team secured its fourth stage victory at this year's race.
“I’m sorry, I can’t believe that I’ve won a stage of the Tour de France," an emotional Van Aert said about his first individual Tour de France stage win.
"It’s above anything else. I’ve discovered this race in the last ten days. Winning at my first attempt is incredible. It became quite nervous in the finale. Luckily we stayed at the front with Steven Kruijswijk and Dylan Groenewegen.
"I went 250 metres from the finish. It was close with Viviani at the end, but one centimetre is enough as long as I won it.”
Tony Gallopin (AG2R-La Mondiale), Michael Schär (CCC), Natnael Berhane (Cofidis), Anthony Turgis (Total Direct Energie), Mads Würtz Schmidt (Katusha-Alpecin) and Odd Christian Eiking (Wanty-Groupe Gobert) escaped soon after the flag dropped but were absorbed within the final 30 kilometres as the echelon fireworks played out in the peloton behind.