Martin, riding for UAE Team Emirates, had been defeated in a sprint finish yesterday by Julian Alaphilippe and seemed determined to make amends today.

He duly launched a devastating attack with three kilometres remaining on the summit finish at the end of the 130.5km stage from Grenoble to Valmorel.

Overall race leader Gianni Moscon was dropped and it was left to his team-mate Thomas to continue the Team Sky challenge.

Thomas attacked from the chase group with 1km left and dropped rivals including Mitchelton Scott's Adam Yates and Ag2r La Mondiale's Romain Bardet, from Britain and France respectively. 

He ran out of road to catch Martin, however, as the Irishman enjoyed his first victory in UAE Team Emirates colours in a time of 3 hours 21min 19sec.

Thomas crossed four seconds behind in second to move into the overall lead with two stages left.

Yates, whose brother Simon led for most of the Giro d'Italia last month before falling away in the final week, finished third, another 11 seconds back.

Thomas now leads by 1:09 overall over Italy and BMC Racing's Damiano Caruso, who finished seventh today, as well as Moscon.

Martin is still outside the top 10 overall while Yates moved up to sixth. 

The peloton will take a 110km mountain stage on the penultimate day of racing tomorrow from Frontenex to La Rosière Espace San Bernardo.