On the final climb of the category 2 Col de Manse, and the tricky descent that preceded the line in Gap, Froome and Porte withstood a number of attacks from Alberto Contador, one of which caused the Spaniard to crash and Froome to swerve around into the grass.
Though Froome had to unclip and drop his bike, the Sky captain came away unscathed, although with a significantly higher heart rate.
Porte was at his side, quick to lead him down the mountain and bring back their previous companions, including second placed Bauke Molleman (Belkin) and Nairo Quintana (Movistar).
"They threw everything at us on that last climb, but we expected that. Katusha was absolutely brilliant there, they took it up and made it a hard climb. There are some guys on GC that got gapped today."
Porte wasn't sure that Contador gave everything he had into the numerous attacks. "I think he knew even if he got a gap it was goign to come back, I don't think he attacked full gas," he said.
The surges did help to shuffle the top 10 around. Losing time were Michal Kwiatkowski, at 1:39 from Quintana in the young riders for the stage, and Laurens ten Dam (Belkin).
"I didn't know Ten Dam was.. how far back was he? If they want to ride for second place, then good on them. I'll support them in that."