Hello and welcome to live coverage of stage 5 of the Giro d'Italia. It's the first mountaintop finish as the riders head to the Apennine ski resort of Abetone for what could be a thrilling finale.

New top three: 1. Contador, 2. Aru +2, 3. Porte +20. So, just two seconds in it... perfectly poised for us spectators.

So that's a four-second bonus for Aru, which is a small victory but a victory nonetheless. Contador takes over the pink jersey from Orica-GreenEdge though. Time splits coming up.

Chavanel just holds on for second place - by half a bike - as Aru mops up the final bonus seconds for third place ahead of Contador and Porte. What a finale.

Sylvain Chavanel will take second place. Dillier and Domont appear to have been caught. The IAM rider is almost there - just as Aru attacks behind...

His mouth agape, Jan Polanc roars onto the final straight before crossing the line with his arms aloft. Victory for the 23-year-old Slovenian!

Polanc can almost taste the victory now as he approaches the finish straight...

Ryder Hesjedal also has a pop - yet again, this is a mere aside to the main events.

Giovanni Visconti attacks from the pack - but that's just a detail.

Movistar are leading the chase in the 'pack' with no sign of Uran as yet. Meanwhile, Polanc is riding to a first professional win. Chavanel has yet been caught by the Aru group.

Polanc is out of the saddle and grimacing with intent as he rides towards the 2-to-go banner. He's still in the big ring - and has 1:45 over the chasing group, who have a whole minute over the Uran group.

Rigoberto Uran the big loser again today - he just cannot match the explosiveness of Porte, Aru and Contador.

Advantage Astana: Landa manages to catch the big three, so Aru now has a team-mate with him. With Chaves dropped, Contador is now the virtual maglia rosa.

Porte and Aru have caught Contador, who's out of the saddle and in the big ring. They catch Domont under the 5-to-go banner - and then Porte has a dig! The gap for Polanc is just two minutes now - or 1km.

ATTACK: Alberto Contador jumps on the pedals! Aru and Porte respond, but they're a few bike lengths back...

It's Paolo Tiralongo riding hard on the front for Astana, who have cut the gap to three minutes. The peloton has been whittled down to about 40 riders now. Siutsou is with Porte now.

Astana now on the front of this climb - but it's not steep enough for any big attacks it seems. Carlos Betancur of Ag2R-La Mondiale has been dropped - as has Simon Clarke, the pink jersey.

Another attack from Pirazzi! The Italian is indefatigable. Polanc is now in the forest section, and he has 3:30 over the pack. Pirazzi catches Tvetcov, but the pair are then swept up by the peloton.

Landa and Pirazzi have been caught by the peloton, which is being led by Tinkoff-Saxo. Porte is isolated, with just one team-mate a few riders behind.

Chavanel has definitely distanced Dillier, but he's struggling out of the saddle now. He's about 30 seconds down on lone leader Polanc.

Another attack by Astana, who send Mikel Landa up the road. The Spaniard catches Pirazzi. Up ahead, Polanc is now on the 10% section.