So, Simon Yates will be joined by Enric Mas and Miguel Angel Lopez on the final podium, as Steven Kruijswijk and Alejandro Valverde drop to fourth and fifth.
Escaldes-Engordany - Coll de la Gallina
Vuelta a España - 15 September 2018
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Here was the top eight in today's stage - with Quintana and Valverde completing the top 10 over three minutes down.
Quintana and Valverde come over the line 3'09" down and so the Spaniard will drop to fifth on GC. A terrible day for Movistar.
I thought Yates might celebrate or punch the air, but he crossed the line with a faint smile and then same to an almost stand-still. He was clearly at the limit of his powers - but the job is done.
Simon Yates (Mitchelton-Scott) crosses the line around 20 seconds down to secure his maiden Grand Tour victory.
Lopez launches his sprint but Mas closes the door and then takes the win. Victory for Enric Mas (Quick-Step Floors).
It's impossible to call this one... and it looks like Mas is going to lead ut out...
Mas and Lopez are already starting to play games - chatting to each other and playing cat and mouse...
Under the banner they go and our two leaders still have 20 seconds.
Lopez won two stages in last year's Vuelta so this could be his third. Mas, meanwhile, has never finished higher than third place in a Vuelta stage, so he should change that today. Unless Yates turns things round...
Yates is closing the gap - could he be up for a second stage win? Meanwhile, Uran and Pinot drop Kruijswijk...
Kelderman has now been dropped as Kruijwsijk, Uran and Pinot continue the chase. Poor Valverde, he's pedalling squares and has Quintana constantly slowing up for him.
De la Cruz has been dropped by the chasers. They trail the two leaders by 58 seconds but have 1'35" on the collapsing Movistar duo. But they're of no interest to Kruijswijk - he needs to cut the lead of Lopez and Mas or wave goodbye to his podium place. And then remember there are bonus seconds up for grabs too...
As things stand, Valverde is down to fifth and Kruijswijk down to fourth. Mas is second ahead of Lopez. Yates, who will win this Vuelta, is 20 seconds behind the two leaders.
Quintana finally notices that Valverde has gone, so he drops back to pick him up. But they're well back now and it's now Kruijswijk who leads the chase with Pinot, Uran and Kelderman. They are about to catch De la Cruz.
Valverde has been dropped! Quintana has no idea and continues tapping out a tempo on the front of the chase group... disaster for Movistar.
Yates has Mas and Lopez in his sights. You sense that he may well go for this and not give any gifts.
Yates is 10 seconds down and the Valverde chasing group are 50 seconds down. De la Cruz is 42 seconds down so in no man's land.
Yates has been dropped again by the two others - he seems to be caught in two minds as to whether he should go for this, or take it easy.
Yates has rejoined the two leaders just after the 6km to go banner.
David de la Cruz attacks from the chasing group in search of Sky's first stage win of this race.
Yates, who doesn't need to ride this one agressively, is happy to continue at his own pace as he lets the podium chasers Mas and Lopez rides clear.
Quintana is the first to be dropped - although he's probably going back to help his team-mate Alejandro Valverde, whose place on the podium is in threat from both Mas and Lopez.
We're onto the Cat.ESP Coll de la Gallina (7.3km at 8.7%). It has some double-digit ramps and finishes at the Santuario de Canolich.
The gap is up to 32 seconds as they approach the foot of the final climb.
With 10km to go, here's what the final climb of this year's Vuelta looks like...
The leaders complete the descent and Mas wants to push on. He wants a podium and so has an incentive to keep the pressure up on Kruijswijk, who he trails by 17 seconds on GC. And the gap now? 17 seconds...
Yates leads Mas on the descent and they're about to bridge over to the leading Colombian duo.
Right, we're onto the last descent of the 73rd edition of La Vuelta. Do we have any heart-in-mouth moments in store?
Symbolically, Quintana is momentarily distanced by Lopez ahead of the summit but he's back on as they crest over. Mas and Yates come next while it's Steven Kruijswijk who leads the chase behind. Alejandro Valverde had no answer.
ATTACK: Simon Yates darts out of the back wheel of his twin brother Adam and rides clear of his rivals. Only Enric Mas can hold his wheel - and what a statement of intent from the red jersey.
Lopez rides past his fellow Colombian, but after a little drop of the shoulders, Quintana manages to ride back on and they have opened up a decent gap.
Time for the next climb, the reverse side of the Cat.3 Coll de la Commella (3.6km at 6.3%). Quintana has a slight lead going onto the climb but Lopez attacks from the pack...
Quintana has about seven seconds to play with as the road flattens out a little. It's a gradual downhill from here until the foot of the next climb, where it should all kick off.
Quintana still has a gap but it's nothing to write home about. Perhaps merits a quick Whatsapp but definitely no postcard or letter.
ATTACK FROM QUINTANA: The Colombian tried going up and now he's going to have a pop going down. He has a small gap, but it's the Yates brothers who lead the pack behind.
It comes back together just ahead of the summit and then Mollema finds the strength to dart forward and just - just - pip Lopez for the 10pts. With De Gendt now nowhere to be seen, the Dutchman has closed the gap a little. But it's still a big, big ask.
The gaps are very small. Cataldo hits the wall after his pace-setting for Lopez, who rides on with Mollema and Nibali. They have Majka and De la Cruz in their sights, but right over their shoulders they have the chasing red jersey group.
Majka finished seventh at Ribiera Sacra in Stage 11, second on La Camperona in Stage 13 and fourth at Balcon de Bizkaia in Stage 17. He's always knocking on the door but hasn't get burst through the threshold.
Majka has ridden clear of De la Cruz. Mollema has been caught by the Lopez group, which is just four strong now, with Cataldo and Nibali also in the mix.
Majka and De la Cruz have dropped Mollema now, who is 10 seconds back. The Lopez chasing group is another 10 seconds back and the red jersey pack another 20 seconds back.
Cataldo, Fraile and Lopez have now caught some of the tail-enders of the break, including Nibali. Up ahead, it's Majka, Mollema and De la Cruz who ride as a trio after dropping Kwiatkowski. The other escapees - including De Gendt - are somewhere in between. But the gaps are very small, with the red jersey group now just 40 seconds off the pace of the leading trio.
ASTANA ATTACK: The two men who are with Lopez are in fact Cataldo and Fraile from the break, who dropped back to relay with their leader - and as a trio they ride clear. The Colombian is 2'29" down on GC and needs 31 seconds to jump above Steven Kruijswijk and move onto the podium.
Meanwhile, back with the pack it's Astana who still set a strong tempo, but they have burned another match and so they're down to two riders plus Lopez, who looks like he's chomping at the bit.
It's Kwiatkowski who sets the tempo in the break, looking to open Team Sky's account in this year's Vuelta. It's the first Grand Tour since the 2014 Vuelta that they have not won a stage, although the Pole has twice finished runner-up.
Descending over, it's onto the fourth climb straight away - and it's the reverse ascent of the Cat.1 Coll de Beizalis (7.1km at 8%). Scrap that - it's not the reverse, but the same side. They have done a loop and this completes the loop before they head back and climb the Comella from the reverse side.
Finally, we have confirmation that it was De Gendt who took second place over the last climb ahead of Mollema, Fraile and Cataldo. So that further consolidates his lead in the KOM standings. Unless Mollema pulls off a coup and takes a heap of points over the next three climbs off the back of De Gendt popping extraordinarily, then it's all over in the battle for polka dots.
Kwiatkowski and Nibali are pushing on with Oliviera on this descent - they open up a small gap as the road flattens up, but sit up and wait for their fellow escapees ahead of the final drop to the valley. They caught Herrada and so we're back to 16 riders out ahead, with the Astana-led peloton just over a minute back.
This is a lovely descent through the trees and then on roads hanging on to the side of sheer rock races with some lovely hairpins but many long straights too.
The pack caught Brambilla before the summit, which they crested 1'22" down on Herrada. Meanwhile, Ion Izagirre has been dropped - so he may also be dropping out of the top 10 today along with Gallopin.
Herrada pockets the 10pts for going over the summit of the Coll de Ordino in pole position. He has about 20 seconds over the chasers but it was hard to see what the order was going over for them because we'd gone to distant aerial shots and not closer-up motorbike ones.
Jesus Herrada has attacked from the break and rides with a small gap as he approaches the summit of the climb. An odd move, that. He probably hopes that others would join him, but no one did.
The upshot of the tempo-setting from Astana is that the gap has come down to 1'55" for the 15 leaders and all those chasers - with the exception of Brambilla, at 1'15" - have been reeled in.
Both Yates brothers are gesticulating at the camera motorbike - and then the red jersey rides up ahead of the Astana train and waves the offending bike away. They clearly think that the draft is giving their rivals an unfair advantage in dragging out this main pack and putting everyone else under pressure.
Astana now take it up on the front of the pack with three riders really drilling a hefty tempo. They clearly fancy setting up Miguel Angel Lopez for the win today. They came into the race with high hopes but they have not won a stage yet - although both Omar Fraile and Lopez have come close.
Fabio Aru, who was on the offensive earlier on today, is now off the back of the pack. He's been struggling for a couple of seasons now, and has really not found his feet yet at UAE Team Emirates. On this form, Italy won't select him for the world championships.
The other chase group of Molard, Ion Izagirre, Kudus, Rolland Anacona and Amador are 1'45" down with the pack a further minute back.
The two leading groups have come together again so we have 15 riders out ahead after the chasing group of Dario Cataldo, Omar Fraile (Astana), Nicolas Roche (BMC Racing Team), Nelson Oliveira (Movistar), Amanuel Ghebreigzhabier (Dimension Data), Ilnur Zakarin (Katusha Alpecin), David de la Cruz (Team Sky), Jai Hindley (Team Sunweb) and Jesus Herrada (Cofidis) bridge over. Jose Herrada is trying to bridge over but is 55 seconds down.
Not that this is high on your agenda, but Rafal Majka won the intermediate sprint at La Massana ahead of Mollema and De Gendt. It came at the start of the climb, but that's the nature of today's stage - which boasts 4,000m of climbs in less than 100km.
We're almost onto the next climb, the Cat.1 Coll de Ordino (9.8km at 7.1%). It's a gradual grind that peaks at 8.5% so nothing too wacky. We're hearing that Tony Gallopin was dropped from the pack on the last climb - the Frenchman is in 10th on GC so on course for his highest ever finish in a Grand Tour. But he could drop a few places today...
Confirmation that it was De Gendt who trousered the 10pts over that last summit with once again Mollema settling for second place. That puts the Dutchman into second place in the KOM standings but he still trails the Belgian by a fair gap.
Our six leaders have 15 seconds on a chase group of nine riders: Kelderman, De la Cruz, Zakarin, Herrada, Ghebreigzabhier, Roche, Fraile, Cataldo and Oliviera. The Brambilla/Kudus group is 50 seconds back and the main pack is 2'20" in arrears.
De Gendt is caught by his pursuers so we have six out ahead now: Vincenzo Nibali, Rafal Majka, Michael Woods, Michal Kwiatkowski, Bauke Mollema and Thomas De Gendt .
Nibali, Majka, Woods, Kwiatkowski and Mollema are closing in on De Gendt on the descent. There are groups all over the road - but the gaps are minimal, with just 2'10" separating the Belgian on the front and the main red jersey pack. Although there will be numerous gruppettos further back, I'd expect...
Gianluca Brambilla (Trek-Segafredo), Merhawi Kudus (Dimension Data) and Andrey Amador (Movistar Team) have managed to zip clear of the main pack but their gap is small. De Gendt, meanwhile, crests the summit and takes the 10pts.
De Gendt is riding cannily, knowing that the more points he gets now, the better chance he has of keeping the polka dot jersey. While there's a huge hoard up for grabs, you'd fancy him holding on now.
Panic over for Yates: his twin brother Adam is back in this main pack, which is regrouping with Quintana at its head, as well as Damian Howson. Out ahead, De Gendt has fought fire with fire and ridden clear of the leading group in pursuit of more KOM points.
Meanwhile, out ahead Mollema has been joined by Majka, Nibali and De Gendt. Quintana has now been pegged back by the GC group and already Yates looks isolated. Kruijswijk has George Bennett and Movistar have Quintana, Valverde and Carapaz. It's about 25-strong with another group trying to bridge over.
The Quintana move isn't really coming to anything. Mitchelton-Scott have sent Matteo Trentin, the European champion, forward to try and stick on his wheel. But it's a bit of a mismatch, to be fair. But the pack has all stretched out on these hairpins as a result, so Quintana has forced an early selection.
Meanwhile, back in the main pack it's Mitchelton-Scott who are fronting the peloton, which trails the lone leader Mollema by two minutes. Nairo Quintana is right there on the front, looking as if he may have a pop from distance. A couple of riders so try something - Brambilla and Cherel. AND THEN QUINTANA GOES! Well, well, well, Movistar are really going for this. They have Oliveira in the break, Anacona bridging over, and now Quintana on the offensive.
Jai Hindley (Team Sunweb) and Rudy Molard (Groupama-FDJ) have managed to bridge over to that chasing group. They trail the leading 15 riders by 30 seconds. And out of the blue there's an attack from Bauke Mollema! The Trek rider doesn't want to let De Gendt have the polka dot jersey without a fight - and he's taken this one with a long way out.
Lluis Mas (Caja Rural) is trying to bridge over from the peloton and he's been joined by a handful of riders in Fabio Aru (UAE Team Emirates), Ilnur Zakarin (Katusha Alpecin), Pierre Rolland (EF Education First) and Winner Anacona (Movistar).
The 15 leaders are: Vincenzo Nibali, Gorka Izagirre (Bahrain-Merida), Dario Cataldo, Omar Fraile (Astana), Nicolas Roche (BMC Racing Team), Rafal Majka (Bora-Hansgrohe), Thomas De Gendt (Lotto-Soudal), Nelson Oliveira (Movistar Team), Amanuel Ghebreigzhaber (Dimension Data), Michael Woods (Education First-Drapac), David De La Cruz, Michal Kwiatkowski (Team Sky), Bauke Mollema (Trek-Segafredo), Jose and Jesus Herrada (Cofidis).
It's up and down all day today with hardly any flat. Already, the riders are onto the next climb - the Cat.1 Coll de Beixalis (7.1km at 8%). They tackle this one twice but from two different directions either side of the third climb, the Coll de Ordino.
We spoke to Simon Yates ahead of the stage - and he remains extremely focused and cautious, which is no surprise given what happened to him in the Giro...
Here's how the GC looks going into today's all-important stage with Simon Yates 1'38" clear of Alejandro Valverde and another 20 seconds ahead of Steven Kruijswijk. With Enric Mas and Miguel Angel Lopez also lurking, there's going to be a fierce battle for the podium places... but unless the British leader really cracks, it's hard seeing him relinquish the red jersey.
Loads of big-name riders in this break - including Vincenzo Nibali of Bahrain Merida. The Italian made big strides on the descent. There's around a dozen riders off the front with a handful chasing over.
De Gendt zips clear near the summit to pocket the 5pts. That puts the Belgian 15pts clear of Luis Angel Mate (Cofidis) in the battle for the polka dot jersey. Bauke Mollema (Trek-Segafredo) crested in second place, which puts the Dutchman one point behind Mate in third place. Michal Kwiatkowski (Team Sky) is third over.
The first move comes from Salvatore Puccio (Team Sky) who's joined by Tiejs Benoot (Lotto Soudal), who looks to be setting things up for his team-mate Thomas De Gendt who is in polka dots. They're joined by numerous other riders.
Straight on to the first test of the day, the Cat.2 Coll de la Comella (4.4km at 8.7%).
Here's the official profile of today's brutal stage - six climbs, 53 points for the KOM battle, 13 bonus seconds and 29 green jersey points all up for grabs. Oh, and the red jersey.
Yesterday, Great Britain’s Simon Yates extended his lead in La Vuelta after attacking his rivals with 10 kilometres remaining of the Coll de la Rabassa to finish in second place behind Frenchman Thibaut Pinot in Stage 19 in Andorra.
Hello and welcome to the decisive stage of this year's Vuelta a Espana - a 97km mountain schlep in Andorra that features six categorised climbs and will decide the destiny of the red jersey. Can Simon Yates hold on? We'll find out over the next few hours...