Koenig attacked with two kilometres to go to claim the win on the Alto de Penas Blancas summit finish. Spain's Dani Moreno was second with Roche in third.
Following the Vuelta a Espana's third summit finish, Roche now leads the race with American Chris Horner in second and Moreno third.
Previous overall leader Vincenzo Nibali suffered in the final kilometres of the climb, losing around 30 seconds to the stage winner and dropping to fourth overall.
The Tour finishes on September 15 in Madrid.
(Editing by Stephen Wood)
Share
