Chris Froome fought off attack after attack to preserve his commanding Tour de France lead after stage 17 to Pra Loup.
The Team Sky leader successfully countered attacks (with the help of Ireland's Nicolas Roche) from nearest rival Nairo Quintana (Movistar) early and late on the 161km route from Digne-les-Bains as German Simon Geschke (Giant-Alpecin) won.
Andrew Talansky (Cannondale-Garmin) was second and Riogberto Uran (Etixx-QuickStep) third, but the more significant action took place in the Froome group.
Quintana tried to launch an early escape, but Froome's Team Sky squad hunted him down and when the Colombian climber twice accelerated on the concluding ascent to the small ski resort, Froome chased him down.
The Kenya-born Briton finished seven minutes 16 seconds behind Geschke on the same time as Quintana to preserve his advantage of 3mins 10secs, with four stages remaining ahead of Sunday's conclusion in Paris.
It appears that only Quintana stands between Froome and a second yellow jersey after his 2013 win.
Quintana's team-mate Alejandro Valverde is now third overall, 4:09 behind, after Tejay van Garderen (BMC Racing) was forced to abandon midway through the stage through illness.
He was not the only rider to quit as world champion Michal Kwiatkowski (Etixx-QuickStep), Irishman Sam Bennett (Bora-Argon), Nathan Haas (Cannondale-Garmin) and Jerome Coppel (IAM Cycling) all got off their bikes.
Alberto Contador (Tinkoff-Saxo) lost time with a crash on the final ascent and sits fifth, 6:40 adrift.