However stage nine of the Tour includes two HC climbs, the Col de la Biche and the Grand Colombier before Mont du Chat, as well as four other smaller climbs. You get the big points for that and then you have to see. Just 61 seconds separate him from 10th-placed Rafal Majka of Poland. Beginning with a 16km-long second-category ascent, it contains no fewer than three Hors Category mountains on its 181.5km route.
Direct Energie star Calmejane won the race from Dole to Station des Rousses by acutely timing his drive up the stage's final climb to take a lead the baying peloton could not cut down. He placed eighth on the climb, 26 seconds slower than Aru and six seconds behind Froome.
They will be further tested on Sunday, when the ninth stage takes the peloton through the Jura mountains with three lung-busting climbs in prospect before a unsafe descent to Chambery.
Chris Froome retained the yellow jersey and remains 39 seconds clear of Matthews' countryman Richie Porte in fifth. "I hope there's some exhausted legs among them tomorrow".
The French Direct Energie rider looked to be cruising to victory, but in the final kilometres he cramped on his bike and nearly came to a standstill before eventually finding his rhythm again. It was the second win at this Tour for a French rider, after Arnaud Demare's on Stage 4. Froome managed to stay on his bike and quickly recover.
The corner "sprang up on us a little bit", Froome said. "Probably, you know, could have had the same result with half the distance but it's a nice one to get done", Porte said.
Calmejane has resisted the Dutch rider Robert Gesink, on its heels, when the last climb to the finish. It's not necessary to say that I'm extremely happy. "It would have been so sad to lose the stage like that".
The LottoNL-Jumbo rider finished ahead of Guillaume Martin, who came through in third place.
It was very much Calmejane's day, though, attacking with 6km to go on the last category one climb and taking the polka dot jersey in style with a magnificent solo ride.
"It is going be an important block these next two days but Sunday's stage will be very decisive with a lot of climbing and we will see a lot of damage", said Froome, who won the Tour in 2013, 2015 and 2016.
"It was everything I was dreaming of".