Stage 20 was a 146.5 km trek from Megève to Morzine and was the final mountainous challenge of this year’s race.
In the driving rain some 30 riders broke free to animate the day’s action.
As the race hit the fourth and final climb of the day, the break splintered with Jarlinson Pantano, 2014 Champion Vincenzo Nibali and Ion Izagirre riding clear.
At the top Movistar’s Izagirre made his move and would not be caught again as he masterfully negotiated the descent to take the biggest win of his career.
Froome meanwhile managed to protect his sizeable lead and is now just one processional stage away from joining the elite club of three time Tour de France winners.
He is four minutes and five seconds clear of Frenchman Romain Bardet in the GC, while Colombia’s Nairo Quintana is third overall a further 16 seconds adrift. (Euronews)