Astana's Vincenzo Nibali has won stage 19 of the 99th Giro D'Italia.
The first of two days in the Alps saw a 162km stage from Pinerolo to Risoul.
Thirteen riders went clear with 18kms gone but were soon brought back and Verona and Denilf tried to get away after fifty kilometres.
They were caught and then Kudus, Thomson and Rybalkin tried as did Johan Van Zyl before Diego Ulissi took the intermediate sprint.
A break did form and it included Hubert Dupont, Matteo Montaguti, Bakhtiyar Kozhatayev, Michele Scarponi, Stefano Pirazzi, André Cardoso, Moreno Moser, Johann Van Zyl, Carlos Verona, Stefan Denifl, Marcel Wyss, Diego Ulissi, Tim Wellens, Maxime Monfort, José Herrada, José Joaquin Rojas, Rory Sutherland, Damiano Cunego, Ruben Plaza, Georg Preidler Vyacheslav Kuznetsov, Egor Silin, Ian Boswell, David Lopez Garcia, Mikel Nieve, Nicolas Roche, Jesus Hernandez and Evgeny Petrov.
This group went four minutes ahead and with 63kms left, Michele Scarponi decided to head off on his own.
The Astana rider stayed away for twenty five kilometres and was on his his own when Ilnur Zakarin crashed and ended up in the rocks by a stream with 42.6kms left and after the maglia rosa leader Steven Kruijswijk had crashed on the snow covered part of the mountain.
Scarponi was joined by Maxine Monfort and they were 3.47 on the group including Chaves/Nibali and 5'12" on Kruijswijk and then held up.
For Zakarin, his race was over and for Scarponi, he was ordered to wait up for Vincenzo Nibali so Montfort took over and had a lead of 1.44 with 19kms left.
With Kruijswijk in danger of losing his jersey to Esteban Chaves, Montfort was 48 seconds ahead of Chaves/Nibali and and 2.58 ahead of Kruijswijk with 12.8km left.
Montfort started on the climb to Risoul as Nioali, Chaves, Nieve and Ulissi moved closer and then caught and passed Montfort.
There was 5.5kms left when Nibali put in an attack which Chaves matched. Half a kilometre later and Nibali attacked again and was still clear going into the final kilometre.
Undaunted, Nibali continued to press and he took the win in 4.19.55 with Mikel Nieve second, Esteban Chaves and Diego Ulissi.
Valverde came in 2.11 down and Kruijswijk came home 4.53 down and it was Esteban Chaves who leads Nibali by 44 seconds going into the penultimate stage.