Hola and welcome to live coverage of stage 20 of the Vuelta a Espana - and it's the big one: four Cat.1 climbs in a 176km ride from San Lorenzo de El Escorial to Cercedilla.

Now Aru comes to the front with Landa and they've upped the tempo considerably. There's a small gap back to Dumoulin!

Visconti have been joined by De Marchi in their pursuit of Plaza. Astana are now on the front of the pack with Tinkoff-Saxo and Katusha.

Numerous riders off the back of the peloton already on this climb. Remember - they're riding a full 12 minutes behind the lone leader, Ruben Plaza. The Spaniard still has 2:20 over the chasers, who have Visconti out just ahead.

After a flurry of attacks in the break, it's now Giovanni Visconti who has edged clear for Movistar.

Back with the main pack and it's Astana's Dario Cataldo who leads alongside a couple of Movistar riders and Giant riders. The big guns keeping their powder dry for now.

Kenny Elissonde now stretches his legs for FDJ. Bennett is in pursuit before Sergio Henao takes it up.

Now Bennett attacks - and he's being pursued by a BMC rider and then Ventoso and Dombrowski. They're going to bring him back. Plaza now has 2:48 so riding very well.

Reza has been caught and past as George Bennett (LottoNL-Jumbo) and Joe Dombrowski (Cannondale-Garmin) set a fast tempo.

Cannondale-Garmin are active in this chasing group, which has shed a few riders now the gradient has gone up again. Reza still out ahead in pursuit of lone leader Plaza.

Plaza is onto the second ascent of the Cat.1 Puerto de Morcuera. Reza actually managed to edge clear of the chasing group a second time lucky so the rangy Parisian is in pursuit. The pack is still 12 minutes down.

The road is heading up but the third climb has not yet officially started for Plaza. MTN still drive the pace in the pack.

The MTN-Qhubeka team of Louis Meintjes have come to the front of the pack to help lead the chase. That's because Frenchmen Romain Sicard and Kenny Elissonde - both in the break - are a threat to his 10th place on GC. Europcar's Sicard is 19:21 down and FDJ's Elissonde is 19:36 down - but with the 10-odd minutes they have today, that puts them within a couple of minutes of the top ten.

Plaza's lead is up to 2:10 over the chasers and 12:20 over the main peloton. It's the quiet before the storm.

Kevin Reza of FDJ is the latest of the escapees to have a dig from the chasing group. Zubeldia was brought back, as is Reza.

Plaza still has 1:45 over the chasers after stretching the lead back out. He's looking good but still may pay for it on the next two climbs.

Haimar Zubeldia (Trek) has edged ahead of the chasing group, which has come back together again after those earlier splits. The Basque veteran led the stage that Joaquim Rodriguez won last week right until the last couple of kilometres. He also got pipped by Nico Roche for the win two days ago. He has since signed a new contract with Trek for next season so is clearly feeling up for this.

The next categorised climb is in fact the previous one done in reverse - the Cat.1 Puerto de la Morcuera.

The chasing group has split up, which is no surprise because it's just way too large to be effective as it is. Plaza is on that uncaterorised mound now - the Alto Cerro San Pedro - with an advantage of one minute over the nearest chasers. "He's bitten off more than he can chew going off so early," says Sean Kelly.

Plaza's lead has dropped to under two minutes now that the road has levelled out following the descent. There's an uncategorised mound ahead of the next climb so it will probably come back together soon. Back with the pack, some of the pretenders to the crown will have to do something on the next Cat.1 climb or it will be too late - so expect fireworks in about 45 minutes.

So, those 38 chasers are: Adam Hansen (Lotto-Soudal), Jaco Venter (MTN-Qhubeka), Lawrance Warbasse (IAM), Dani Navarro (Cofidis) Jay McCarthy (Tinkoff-Saxo), José Gonçalves (Caja Rural), Eduard Vorganov (Katusha), Moreno Moser (Cannondale-Garmin), Yukiya Arashiro (Europcar), Kevin Reza (FDJ), Andrey Amador (Movistar), Haimar Zubeldia (Trek), Carlos Quintero (Colombia), Joe Dombrowski (Cannondale-Garmin), Alexis Gougeard (Ag2r-La Mondiale), Sergio Henao (Team Sky), Andrey Zeits (Astana), Giovanni Visconti (Movistar), George Bennett (LottoNL-Jumbo), Luis León Sánchez (Astana), José Joaquín Rojas (Movistar), Pello Bilbao (Caja Rural), Nelson Oliveira (Lampre-Merida), Alberto Losada (Katusha), Matteo Montaguti (Ag2r-La Mondiale), Alessandro de Marchi (BMC), Valerio Conti (Lampre-Merida), David Arroyo (Caja Rural), Kenny Elissonde (FDJ), Alex Howes (Cannondale-Garmin), Carlos Verona (Etixx-QuickStep), Amael Moinard (BMC), Nicolas Roche (Team Sky), Jelle Vanendert, Jasper De Buyst (Lotto-Soudal), Alex Cano (Colombia), Romain Sicard (Europcar) and Fran Ventoso (Movistar).

David Arroyo (Caja Rural) has crashed on the descent and is waiting for a new bike. He'll have to fight back on to the break now - and that will dent his chances of entering the top ten today.