"I kind of expected a little more but it's a long way to go", said Porte, who described Aru's attack on the mountain top finish to La Planche des Belles Filles as "incredible".
Robert Gesink and Guillaume Martin were second and third on the stage respectively.
"I'm not really pushing myself for victories because I want to break the record of Erik Zabel, I just want to keep it coming, stay relaxed and get the best from myself and for the team in the sprints, and then see how far that can get me".
Dutchman Robert Geesink was second while Chris Froome retained his overall lead after the group of favourites finished together 50 seconds behind the victor.
Before the start of this Tour a friend of mine, Philip Finegan, asked me if I wanted him to bring me over anything from Ireland, so I asked him to bring some porridge for my pre-race breakfasts, as you do.
The only downside for Froome was allowing Aru to take 20 seconds out of his advantage and the Italian is someone the leader will be keeping a close eye on. You can take on the full race or shorter sections - either way you'll have VIP access along the course. "There are more sprints to come, I'll take my revenge", he said following the sixth stage, where he had to squeeze down an nearly imperceptible gap next to the safety barriers alongside Norwegian Edvald Boasson Hagen in order to contest the sprint.
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Tour de France stages such as those we raced on Friday are anything but recovery days for general classification riders like me.
Two days ago, there was a crash in the final kilometre of the stage even before Sagan's elbow on Cavendish, a victor of 30 Tour stages.
"This weekend is the first real big shake up".
Tomorrow we have a first-category climb to the summit finish at the ski station of La Rousse.
However, seven years ago, the Welshman faded badly on the climb, dropping to 31st. But the organizers systematically zoomed in and saw Kittel winning by the slimmest of margins so he got the win and the Green Jersey.