Rui Costa of Lampre has taken stage six of the 67th Critérium du Dauphiné.
A 183km stage from Saint-Bonnet-en-Champsaur to Villard-de-Lans to Vercors saw 159 riders sign on for another day of climbs.
Tim Wellens (Lotto-Soudal) who took the points on the first climb, Andriy Grivko (Astana), Adam Yates (Orica-GreenEdge), Tim Wellens (Lotto-Soudal), Jonathan Castroviejo (Movistar), Alberto Losada (Katusha), Cyril Gautier (Europcar) and Stephen Cummings (MTN-Qhubeka) were in a break which got away after seventeen kilometres but was promptly brought back by the peloton led by race leader Tejay Van Garderen of BMC.
A new group of Vincenzo Nibali and Andriy Grivko (Astana), Wilco Kelderman (LottoNL-Jumbo), Romain Bardet and JC Péraud (AG2R-La Mondiale), Adam and Simon Yates (Orica-GreenEdge), Tony Gallopin and Tim Wellens (Lotto-Soudal), Jonathan Castroviejo, Gorka Izagirre and Rory Sutherland (Movistar), Alberto Losada (Katusha), Tejay van Garderen and Rohan Dennis (BMC), Julian Alapahilippe (Etixx), Rui Costa (Lampre), Cyril Gautier (Europcar) and Stephen Cummings (MTN-Qhubeka), briefly led but suddenly Nibali put in an attack on the Col de Grimone and was jopined by Tony Gallopin, Alejandro Valverde, Tony Martin and Rui Costa.
Chris Froome and West Midlands born Danny Martin along with Andrew Talansky (Cannondale-Garmin), Wilco Kelderman (LottoNL-Jumbo), Romain Bardet (AG2R), Simon Yates (Orica-GreenEdge), Jose Herrada and Benat Intxausti (Movistar), Tejay Van Garderen (BMC), Robert Kiserlovski (Trek Factory Racing) and Jose Serpa (Lampre-Merida) were in a second group on the road 1.25 back, other riders including Alex Dowsett of Movistar and Julian Alaphilippe and Maxime Bouet abandoned.
Onto the category one Col du Rousset and the lead had gone out to 3.25 but with 59kms left was down to just under three minutes. So Nibali attacked once more. This time, Alejandro Valverde and Rui Costa were able to go with the Astana rider but Tony Martin and Tony Gallopin were left to chase, some ten seconds behind.
Nibali took the ten points on the Col du Rousset and in the pouring rain, he lead Valverde, Costa and Gallopin with a lead of just under three minutes with thirty kilometres to go.
Martin dropped back into the yellow jersey group who were three minutes down on the four up front who went over the Col de Villard-de-Lans.
British rider Simon Yates of Orica GreenEdge went off the front of the peloton to try and catch Nibali's group who were 2.23 ahead with six kilometres left.
Romain Bardet, the winner on stage five, crashed and landed in a puddle but was able to continue in a chasing group which included Dan Martin.
With 3.8kms left, Tony Gallopin of Lotto Soudal nipped clear and Valverde, Nibali and Costa let him go.as they got onto the final climb.
There was 1.5kms left when Nibali finally decided to go after Gallopin and caught him a hundred metres later. The 2014 Tour De France winner went past in a stage that had been full on all day.
Rui Costa came up to Nibali and was looking stronger. Nibali allowed him to pass and it was Rui Costa who won in 4.23 but Nibali who finished seven seconds down was the new race leader as Tejay Van Garderen came home 2.12 down.
Third was Valverde some thirty seven seconds down with Gallopin fourth, followed by Simon Yates who was 1.23 down, Dan Martin who was 1.46 down, Gadret, Benoo with Chris Froome ninth 2.11 down and Benat Intxausti.
Nibali leads the race by 29 seconds from Rui Costa with Simon Yates fourth, Chris Froome seven and Dan Martin ninth.