Defending champion Jonas Vingegaard kept the overall lead of the Tour de France on Sunday crossing the finish line in the second of four Alpine tests wheel to wheel with Tadej Pogacar.
Dutch climber Wout Poels won the 15th stage, raced in the shadow of Mont Blanc.
Vingegaard remains 10 seconds ahead of Pogacar.
Carlos Rodriguez is more than five minutes behind in third, but the 22-year-old Spaniard, on his first Tour, tightened his grip on a podium place as Australian Jai Hindley dropped to fifth with Briton Adam Yates rising to fourth.
The 179km run from Les Gets to Saint Gervais Mont Blanc was again dominated by the duel between the two favourites and by a series of falls.
Pogacar twice attempted characteristic blistering late attacks. Vingegaard caught up both times and then sped past approaching the line, only to slow and look his Slovenian rival in the eye as they crossed together.
Monday is a rest day ahead of a potentially decisive individual time-trial on Tuesday which is followed by another Alpine stage on Wednesday.
Pogacar said he was looking forward to the next two stages.
"Tuesday's time trial will provide a shake up, and Wednesday's stage has some of the hardest climbs in cycling," said the 2020 and 2021 Tour winner.
Sunday's winding route through wild Alpine meadows and valleys featured five mountains but the expected fireworks were doused by an early mass fall.
Rowdy roadside fans have caused continual havoc on this Tour and on Sunday a clumsy spectator brought down half the peloton after stepping out into the road about 60km in.
An escape group built an eight minutes advantage that the chief pretenders showed no appetite to close in sizzling summer temperatures.
Raced within view of massive Mont Blanc with its snow-capped peak French hopes were again battered a day after Romain Bardet crashed out, with David Gaudu dropped on the last climb.
Riders again tangled with motorbikes. On Saturday one had blocked a Pogacar attack and on Sunday Krists Neilands was knocked over by a motorbike delivering water.
Colombia's EF rider Rigoberto Uran ran off a mountain road only to get back up and carry on and there were incidents of riders taking wrong turns.
Bryan Coquard, the French sprinter, broke his handlebars but, with his team car unable to reach him with a replacement, still negotiated a mountain descent.
dmc/pb/nr
