Columbian Egan Bernal has moved into the overall Tour de France lead as stage 19 was called off due to hail and snow in the Alps on Saturday (NZ time).
Team Ineos rider Bernal, who started the day 90s behind Julian Alaphilippe, led the Frenchman by two minutes during the climb up the Col de L'Iseran when the stage was cancelled.
Alaphilippe began eating back into the lead with a brilliant descent, only to be told to stop riding after organisers called the race off because of the dangerous conditions ahead.
They later confirmed that there would be no stage winner for the first time in the race's history.
There was confusion on the roads initially, as the riders were descending in ideal conditions, but up ahead even the use of bulldozers was unable to make the road safe, while a small landslide also made conditions hazardous.
The race timings were taken from the top of Col de l'Iseran and unofficial timings give Bernal a lead of 45s going into the final mountain stage, as he seeks to become the first Colombian to win the Tour.
Defending champion Geraint Thomas, who started the day 1m 35s behind Alaphilippe, stayed third overall after reaching the Col de l'Iseran, 2770m above sea level, about one minute adrift of Bernal.
Team Ineos sports director Nicolas Portal said that Bernal would have liked the race to continue with one more climb to come before the finish in Tignes.
"We had the race in our hands and Egan would have liked to ride the last climb but the riders' safety comes first, ASO [organisers] did a great job," he said.
"We wanted to smash it today, and the guys were super motivated. It would have been ideal if the race could have continued because even if he had reduced the gap in the descent, Julian would have suffered in the last ascent."
Alaphilippe, speaking from Val d'Isere, where the riders took shelter in a tunnel, conceded defeat.
"I was expecting this. I gave everything but I was beaten by a stronger rider," the world number one said.
Alaphilippe had offered France their only chance to celebrate a first home-grown winner since Bernard Hinault in 1985 after Thibaut Pinot, widely regarded as the only rider able to challenge Bernal in the mountains, abandoned early in the stage with a thigh injury.
Pinot left the race in tears, with former winner Bradley Wiggins, witnessing the scene from a TV motorbike, saying: "I'm heartbroken, it's like watching a dog die."
Hours afterwards, it was announced that the penultimate stage will be shortened by 71km because of landslides and severe weather warnings.
"Following difficult weather and landslides forecast for tomorrow [Saturday], the route of the 20th stage of the Tour de France has been modified," read a statement from Le Tour.
Kiwi George Bennett is 20th on the overall standings.
Reuters
