“I was running low on sugars,” Froome told reporters. “I am thankful to have Richie with me he did a super, super job.”
Froome and Porte were each given a 20-second penalty for illegal feeding as organisers said the riders were not allowed to take food or liquid from the team car during the final six km of the stage.
However, Froome still leads Alberto Contador, the 2007 and 2009 Tour champion, by 5:11, after the Spaniard struggled to keep the pace in the final ascent following a bold but brief attack on the treacherous descent from the Col de Sarenne.
Contador, who was 11th on the stage, 57 seconds behind Froome, heads Colombian Nairo Quintana by 21 seconds overall after the Movistar climber, targeting a podium finish in Paris, took fourth place 2:12 off the pace.
“Throughout the entire race we’ve said that we wanted the overall win and we were not afraid of risking it all to get it and so we did today,” said Contador’s Team Saxo Tinkoff sports director Fabrizio Guidi.
“But the legs just weren’t good enough to finish it off. We can be disappointed and everyone’s a lot wiser after the stage but if you never try, you never win."