Stage 12: Pau-Peyragudes, 214.5km
Romain Bardet sprints clear to win stage 12
Chris Froome slips to second as Fabio Aru takes lead
Froome cracks on brutal final climb to finish
Commentary on BBC Radio 5 live sports extra from 14:00 BST
What a day.
A day that looked like Team Sky had shut everything down and delivered Chris Froome to yet another yellow jersey.
But his rivals had other ideas - Romain Bardet taking the stage, Fabio Aru taking yellow.
A word too for Steve Cummings, who attacked bravely on the 50th anniversary of Tom Simpson's death.
This Tour suddenly became a bit of a thriller.
Catch you tomorrow, when Froome's rivals will surely look to attack again.
Chris Froome has held the yellow jersey since stage four but he won't be part of the podium celebrations today.
Instead, Astana's Fabio Aru will pull on the maillot jaune shortly.
Although the Italian is the new race leader, it's perhaps an even better day for stage winner Romain Bardet, who has just left the stage.
Bardet is just 25 seconds behind now and his AG2R team are looking strong, while Astana have been hit by injuries.
For now though, a superb effort from Aru.
Prior to that remarkable finish to the stage, it looked like British champion Steve Cummings could pull off the most impressive victory of his career as he led up the penultimate climb.
Ultimately, the power of the group behind, drive by Team Sky, told.
Here's Cummings, speaking to ITV4: "I thought it was a bit beyond me this morning but you never know - I wanted to try and probably needed six minutes at the bottom of the Peyresourde.
"I gave it my all but its quite nice being in front to cross the climbs alone, it's a good feeling.
"I managed to get in the break without much dificulty, it was a good combination, everyone was rolling through but it was just the length of the stage and Team Sky kept the gap quite low.
"I'm surprise Froome has lost yellow but it's still very close and there's a lot of racing to be done. It's bike racing - anything can happen."
For all Team Sky's dominance over the Porte de Bales and Col de Peyresourde, when it came to the final climb Chris Froome simply did not have the kick to stay with his rivals.
His team-mate Mikel Landa actually looked stronger on that final climb, and finished ahead of his leader.
For anyone worried this Tour would be a procession for Froome, worry no more.
For anyone worried a third straight Tour title would be beyond Froome, your fears could have been realised today.
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Confirmation that Fabio Aru has seized the yellow jersey off Chris Froome.
Froome finished 20 seconds behind the Italian and, with those four bonus seconds Aru got for third, he now leads the Briton by six seconds overall.
Stunning.
Oh! Tremendous kick from Romain Bardet on this brutal rise to the finish line.
He comes past Fabio Aru and Rigoberto Uran, holding them off to win the stage and take crucial bonus seconds.
Aru holds on to take four bonus seconds - and that could be enough for yellow.
Froome is really struggling here as the clock keeps ticking - he's lost the jersey, surely.
Image source, ReutersThe Frenchman has surpassed Aru and is going for the win...
Froome is lagging. He could lose the yellow jersey here.
The Italian has a lead into the final 200m, followed by Bardet and Uran.
Froome is being distanced!
As quick as he went, George Bennett was quickly brought back by Mikel Landa.
Final stages now as we're into the final 400m.
George Bennett goes, taking the rest of the group by surprise.
Final kilometre of this one - all the favourites together so no major time gaps today.
But bonus points and the glory of a stage win on the line.
Dan Martin is onto Chris Froome's wheel.
The former Liege-Bastogne-Liege winner is excellent in steep finishes.
Ireland's Dan Martin trying to dig in and move up the outside.
Does he fancy this stage win?
Aru up out of his seat, but keeping pace with Froome.
Yates doing well at the back to stay in contention.
I think this is going to end in a very slow-motion sprint.
After racing through that descent, the leaders are now onto the final climb, just 2km to go.
Nieve swings off for Sky, leading Landa to marshall Froome.
It's just 2.4km this climb, but an average gradient of 8.4% is the real kicker.
That leading group is Nieve, Landa, Froome, Aru, Bardet, Uran, Martin, Yates, Meintjes and Bennett.
So all the GC contenders - minus Fuglsang, Contador and Quintana - from the start of the day are still up there and will battle for the stage and crucial time on GC.
The leaders move over the summit of the category one Col de Peyresourde.
They'll have a rapid descent now before the final summit finish.
Which looks a little like this...
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