So, Sicard are now 9th and 10th on the GC after their part in the breakaway. Job well done ahead of the key mountain stages coming up. Otherwise, no change with Aru still 57 seconds ahead of Rodriguez and 59 seconds clear of Dumoulin.
Calatayud - Tarazona
Follow the Vuelta a España live with Eurosport. The Vuelta a España race starts at 12:13 on 4 September 2015. Find Vuelta a España results, calendar, standings and table. Get all the info on the teams to watch.
Keep up with top cyclists and big names in Cycling. Fans can read the latest Cycling news headlines, interviews, expert commentary and watch free replays. Don’t miss upcoming Cycling races. Make Eurosport your go-to source for sports online from Cycling to football, tennis, snooker and more. Enjoy live streaming of this season’s top sports competitions.
The peloton crosses the line 4:47 down on the winner, Nelson Oliveira. Updated GC coming right up...
The other escapees cross the line 1:01 down on the stage winner, with Jules Simon of Cofidis pipping Nico Roche of Sky for second place.
That's the first pro win for 26-year-old Nelson Oliveira (Lampre-Merida).
Oliveira zips up his jersey, takes a bow then punches the air as he crosses the line for the biggest win of his career.
Arashiro driving the break for his team-mate Sicard, who stands to gain a lot today. Meanwhile, Oliveira passes under the 1-to-go banner.
Orica-GreenEdge are now leading the chase in the pack - their man Esteban Chaves' fifth place on GC is under threat.
The win is Oliveira's to lose - even though there's an uphill rise before the line. He now has 1:05 to play with.
Messrs Sicard and Brambilla - currently 13th and 14th on GC - could move into the top five tonight. The pack still trails by five minutes.
Oliveira is, of course, the Portuguese national time trial champion - a status that's putting him in the driving seat right now. He still has a minute to play with so he can almost reach out and touch the podium.
Oliveira still has 58 seconds - he really could do this. Under the 7-to-go banner as Terpstra leads the chase with Lampre's two other riders - Conti and Plaza - weighing him down.
The Lampre-Meride sporting director Orlando Maini has his window down and is banging the car door with his palm as he shouts encouragement to his lone leader, Oliviera.
Arashiro is leading the chase with Europcar team-mate Sicard, and they have Oliveira's team-mate Plaza sandbagging with gusto. Terpstra edges forward. They need to do something soon or it will be too late. Our lone leader now has 53 seconds.
Oliveira continuies to open up his lead as the road flattens out. He pow has 45 seconds but will he hit a wall? Riders like Terpstra and Cummings know how to time trial to the line from distance and so they would still have their say...
Astana leading the peloton and not getting too stressed. The red jersey of Aru is not in jeopardy - and besides, there are three big mountain stages coming up.
He now has 35 seconds. Oliveira is laping up this descent.
Oliveira has 15 seconds on the chasers and a whole five minutes over the pack. He or one of his 23 pursuers will win today.
Nelson Oliveira has pinged off the front on this descent. The Portuguese has been a real live wire in this Vuelta. He has about 10 seconds over the others.
This could be a chance for Jose Joaquim Rojas to get an elusive win for Movistar. The 35-year-old Spaniard has never finished higher than third place in nine Grand Tours...
Poljanski has been caught by the first wave of escapees, which includes Cummings and Roche. The pack is still 4:30 down so this one will go the distance.
Poljanski has taken the maximum 5pts going over the summit of the climb as the two Cofidis riders - Bagot and Simon - lead the chase. The Pole only has 15 seconds to play with.
Kevin Reza is sitting on the back of this group, which has reformed in its pursuit of lone leader Poljanski. The Frenchman has quite a kick and could be the man to watch if this goes to a sprint for the escapees.
Pojlanski has 25 seconds over his fellow escapees as numerous riders bound clear in pursuit. It's certainly time to shake things up and force a selection.
Now Pawel Poljanski dances clear of the break as the road flattens out a little. He's been fairly active in this second week of the race.
Oliveira and Chavanel are joined by De Marchi and then the rest of the escapees. Their attempt at breaking free did not succeed - although Oliveira has not given up and continues riding high tempo.
We're on the Cat.3 Alto del Moncayo (8.5km at 4.5%) and the gap is back up to 3:40 now for the leaders.
ATTACK: Oliveira and Chavanel ping off the front at the start of the climb.
Arashiro, Roche and Terpstra set the tempo on the front of the break - and Arashiro looks set to take the intermediate sprint but sits up to allow Brambilla to steal it from right under his nose. Sicard takes third. The bonus seconds means Brambilla moves above Sicard in the virtual GC.
De Marchi is not happy with the work being done by some of these escapees. Many of them are passengers, which is understanding given the size of this group. The gap is down to 3:15 and so it's touch and go. "Difficult to know for the moment," is Sean Kelly's take on things. "It depends on how well they work together."
Astana have reduced the gap to 3:50 to nullify the threat posed by Sicard and Brambilla. Giant-Alpecin will be grateful they don't have to do any work - if things work out nicely, John Degenkolb may have a last chance for a victory before Madrid.
The peloton is strung out in one long single-file line as the riders complete this gradual downhill. Meanwhile, the break has reached a little peak ahead of the intermediate sprint.
The gap is 4:40 now for the 24 escapees, which is promising for one of these two dozen riders - they have a real chance of staying out till the end today.
It's a cloudy day in northeastern Spain today and there's also some blustery wind reported at the finish - that should spice things up a little. It's a straight finish that comes after a little uphill drag.
Astana and Movistar set the tempo on the front of the pack. Nairo Quintana was in trouble earlier today after being distanced on the opening climb. The Colombian has been struggling with illness since the rest day.
CRASH: Iljo Keisse (Etixx-QuickStep) hits the deck. He was involved in an early attempt to break away today.
The gap is up to four minutes now as the riders approach the feeding zone. They're still on this long, gradual downhill ahead of the intermediate sprint and the third and final categorised climb of the day.
I've just spoken to Sean Kelly before he heads into the commentary booth with Carlton Kirby for Eurosport and he thinks Astana will be motivated to bring this break back not simply because of Sicard and Brambilla and the threat they pose to Aru on GC, but also because of the presence of Roche and Henao of Team Sky, which could help their rivals in the team classification.
The gap is nevertheless creeping up for the 24-man break: 3:25 now. This is wonderfully poised.
Romain Sicard's presence in this break may be why Astana are keeping the gap to below three minutes. Even the Frenchman ruled out featuring strongly today, as he told lavuelta.com this morning: "Yesterday I was a bit hungover from my efforts in Andorra. I hope I have recovered for the hard weekend ahead of us. I 'm proud to have taken my chance in the queen stage of this Vuelta. Now I'm going to play it day by day and see where it takes me. Today is ideal for a breakaway and obviously, with my GC position, I won't be part of it."
British fans will be glad to see Steve Cummings in this break. The 34-year-old MTN-Qhubeka rider was involved in a break earlier in the race and looks once again to add another Vuelta win to his growing list of career achievements. Earlier in the summer he won a stage on the Tour de France after outfoxing Frenchmen Thibaut Pinot and Romain Bardet in Mende.
It's doubtful Astana will let this break gain too much of an advantage what with the presence of Sicard and Brambilla in it: the pair are 6:41 and 6:42 down respectively on race leader Fabio Aru and the Sardinian's team-mates will be leaving nothing to chance. A reminder that Aru leads Joaquim Rodriguez by 27 seconds on GC with Tom Dumoulin a further three seconds back.
Two withdrawals filtering through: Mattia Cattaneo (Lampre-Merida) and Mitchell Docker (Orica-GreenEdge).
Plaza doubles up by bagging the maximum 10 points over the top of the Alto de Beraton. That means he leapfrogs Mikel Landa (Astana) into second place in the KOM standings. Plaza now has 27 points to Omar Fraile's 55.
So, Lampre have three riders in Plaza, Conti and Oliveira, while the likes of Sky, Ag2R-La Mondiale, Etixx, FDJ, IAM and Europcar all have two riders. The gap is 2:20. Interestingly, no riders from Giant-Alpecin here - they're going all in for John Degenkolb at the finish. Can he finally get that 10th Vuelta stage win after all his disappointments this year?
Those extra eight riders are Gianluca Brambilla and Niki Terpstra (Etixx-QuickStep), Kenny Elissonde (FDJ), Maxime Monfort (Lotto Soudal), Cameron Meyer (Orica-GreenEdge), Steve Cummings (MTN-Qhubeka), Yohan Bagot (Cofidis) and Valerio Conti (Lampre-Merida), who join Sylvain Chavanel (IAM Cycling), Nelson Oliveira (Lampre-Merida) and Yukiya Arashiro (Europcar), Alessandro De Marchi (BMC), Mikael Cherel (Ag2R-La Mondiale), Jérôme Coppel (IAM Cycling), Ruben Plaza (Lampre-Merida), Jelle Vanendert (Lotto Soudal), Nicolas Roche and Segio Henao (Team Sky), Davide Arroyo (Caja Rural), Julien Simon (Cofidis), Kevin Reza (FDJ), Jose Joaquin Rojas (Movistar), Romain Sicard (Europcar) and Pawel Poljanski (Tinkoff-Saxo).
Yes, it seems like another chasing group of eight riders bridge the gap too so we have 24 riders out with a lead of almost three minutes on the peloton as we start of the main part of the climb.
The eight chasers are Nicolas Roche and Segio Henao (Team Sky), Davide Arroyo (Caja Rural), Julien Simon (Cofidis), Kevin Reza (FDJ), Jose Joaquin Rojas (Movistar), Romain Sicard (Europcar) and Pawel Poljanski (Tinkoff-Saxo). They have managed to bridge the gap and we appear to have a large group of 23 riders now out in front, so there must be a few extra additions along the way.
The riders are on the nursery slopes of the Cat.1 Alto de Beratón - the big test of the day, although the climb proper is only 5km long at 6%.
We join the race live now with those eight escapees holding a slender 35 seconds over a chasing group, with the peloton a further 10 seconds back.
Nairo Quintana is struggling today. The Colombian was off the back on the climb and needed to be paced back by Movistar team-mate Francisco Ventoso. Quintana has been ill and riding with a high temperature.
The eight leading riders came together before the summit and Plaza took the points over the top ahead of Oliveira and Coppel. Plaza is fourth in the KOM standings on 14 points so no huge threat to current polka dot jersey Omar Fraile of Caja Rural, who leads on 55 points.
Alessandro De Marchi (BMC) rode clear in pursuit of the three leaders, with Mikael Cherel (AG2R-La Mondiale), Jérôme Coppel (IAM Cycling), Ruben Plaza (Lampre-Merida) and Jelle Vanendert (Lotto Soudal) in pursuit.
The average speed for the first hour was 44.6kmph.
Approaching the Cat.3 Alto Collado de Oseja there was still no break as Chavanel tried his luck again, taking Nelson Oliveira (Lampre-Merida) and Yukiya Arashiro (Europcar) with him.
This came to nothing before the peloton split with around 50 riders in the leading group.
No gap came until Sylvain Chavanel (IAM Cycling), Iljo Keisse (Etixx-Quick Step) and Jimmy Engoulvent (Europcar) managed to edge ahead of the peloton after 20-odd kilometres.
It was a fast and furious start this morning with numerous riders trying to ping off the front on the uphill opening segment.
One overnight withdrawal to report on: a sick Maarten Wynants (LottoNL-Jumbo). That left 173 riders to roll out of the start this morning...
Yesterday saw a nail-biting end to an otherwise rather routine transitional stage, with the remnants of a five-man break not caught until the final 200m before Trek's Danny Van Poppel surged clear to take his first Grand Tour stage victory in a slightly uphill bunch sprint in Lleida. Not bad considering the Dutch youngster picked up a puncture 8km from the finish...
Hola and welcome to live coverage of Friday's stage 13 of the Vuelta a Espana - an undulating 178km ride from Calatayud to Tarazona that has breakaway written all over it.