Colombian Daniel Martinez claimed a superb maiden Tour de France stage win as Primoz Roglic extended his lead in the overall standings.
EF Pro Cycling's Martinez went clear of Lennard Kamna in the final metres of a gruelling final climb on stage 13.
Roglic now leads by 44 seconds overall in the yellow jersey, from fellow Slovenian Tadej Pogacar, after the duo dropped their fellow contenders.
Defending champion Egan Bernal of Ineos Grenadiers slipped to third overall.
The Colombian struggled on the brutal summit finish to Puy Mary and is now 59 seconds back on Roglic and 15 seconds down on Pogacar in second.
Frenchmen Guillaume Martin and Romain Bardet, who started the stage third and fourth overall respectively, also cracked and are out of the top 10.
Saturday's 14th stage is a 194km route from Clermont-Ferrand to Lyon.
Top 10 on stage 13
1. Daniel Martinez (Col/EF Pro Cycling) 5hrs 01min 47secs
2. Lennard Kamna (Ger/Bora-Hansgrohe) +4secs
3. Max Schachmann (Ger/Bora-Hansgrohe) +51secs
4. Valentin Madouas (Fra/Groupama-FDJ) +1min 33secs
5. Pierre Rolland (Fra/B&B Hotels-Vital Concept) +1min 42secs
6. Nicolas Edet (Fra/Cofidis) +1min 53secs
7. Simon Geschke (Ger/CCC Team) +2mins 35secs
8. Marc Soler (Spa/Movistar) +2mins 43secs
9. Hugh Carthy (GB/EF Pro Cycling) +3min 18secs
10. David de la Cruz (Spa/UAE Team Emirates) +3mins 52secs
General classification after stage 13
1. Primoz Roglic (Slo/Jumbo-Visma) 56hrs 34mins 35secs
2. Tadej Pogacar (Slo/UAE Team Emirates) +44secs
3. Egan Bernal (Col/Ineos Grenadiers) +59secs
4. Rigoberto Uran (Col/EF Pro Cycling) +1min 10secs
5. Nairo Quintana (Col/Arkea-Samsic) +1min 12secs
6. Miguel Angel Lopez (Col/Astana) +1min 31secs
7. Adam Yates (GB/Mitchelton-Scott) +1min 42secs
8. Mikel Landa (Spa/Bahrain McLaren) +1min 55secs
9. Richie Porte (Aus/Trek-Segafredo) +2mins 06secs
10. Enric Mas (Spa/Movistar) +2mins 54secs
More to follow.