Stage 19 of the Tour de France ended in chaos as an intense hailstorm and a landslide forced organisers to stop the race before the final climb.
Organisers declared that times would be taken from the top of the Col de l'Iseran, putting Team Ineos rider Egan Bernal into the yellow jersey after he crested the highest point of the Tour first after attacking out of the group of favourites on the 126.5km stage to Tignes.
Though the peloton could not ride the final climb, Bernal was taken by car to receive his maillot jaune on the podium in Tignes before any official results had been published.
"It's incredible," said the 22-year-old, now the clear favourite to become the first Colombian to win the Tour, and the youngest rider in the post-war era.
"When I had the jersey and the lion, I wanted to cry. Tomorrow, I will do my best, but it still hasn't sunk in yet."
Bernal had attacked after Geraint Thomas and Steven Kruijswijk made moves in what proved a successful bid to shake off Julian Alaphilippe, who cracked midway up the Iseran.
Provisional results showed Bernal leading by 45 seconds from Alaphilippe, with Thomas a further 18 seconds back in third.
However, several teams were thought to be unhappy with the outcome and the results may take some time to become official.
Commissaries made the call to stop the race after the storms led to a landslide in the valley below Val-d'Isere, with the race route covered in rubble.
Alaphilippe looked frustrated as he climbed into a Deceuninck-Quick Step car as he would have hoped to have taken time back on the long descent, though it will never be known if he could have avoided further losses on the final climb up to Tignes.
Bernal is now the favourite to be on the top step of the podium in Paris after cresting the Iseran around 50 seconds ahead of a group containing Thomas and Kruijswijk, and more than two minutes ahead of Alaphilippe, whose fairytale run in yellow is over.
Riders were told to continue the descent off the Iseran as far as Val-d'Isere, where team cars were waiting for them.
It was yet another dramatic twist in the Tour, hailed as the most exciting edition since 1989, and could well be a decisive one.
Bernal now needs only to survive one final mountain stage on Saturday before potentially celebrating his first Grand Tour victory in Paris a day later.
The 22-year-old would be the first Colombian to win the Tour and the youngest to succeed in the post-war era.
The neutralisation came as a huge blow to Thomas' hopes of defending his title.
The Welshman may have hoped to bridge the gap to his team-mate in the final 30 kilometres but was denied that opportunity.
Earlier in the day, France's best hope of ending a 34-year wait for a home winner, Thibaut Pinot, was forced to abandon the race with a left 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."
His Groupama-FDJ team explained that the 29-year-old, who was fifth overall and still had a genuine shot at the title, sustained the injury when he collided with another rider's handlebars while trying to avoid a pileup on Wednesday.
"We had some hope after seeing him keep up with the best yesterday but the pain was too strong today," said the team's sports director Philippe Mauduit.
"It's extremely tough, he had done everything to be a contender in this Tour."
A team statement said that Pinot, who has won stages on all three grand tours and won the Giro Di Lombardia, a 'Monument' classic, last year, had sustained a 'muscular injury'.
"He had trouble walking last night after finishing the 18th stage with a sharp pain," the statement read.
Pinot climbed into his team car with 87 kilometres to go in the 126.5km mountain trek from St Jean de Maurienne.
He was fifth overall, 1:50 behind race leader Alaphilippe, after riding impressively in the Pyrenees last week.
Pinot had his left thigh strapped by the race doctor but could not pedal properly and threw in the towel after being comforted by his team mate William Bonnet.
The 29-year-old, who was third in the 2014 Tour, was also forced to abandon the Giro d'Italia last year after cracking on the 20th stage while third overall due to a bout of pneumonia.
A stage winner in 2012, as the youngest rider in the Tour, Pinot snatched another stage win at L'Alpe d'Huez in 2015 after he had dropped out of overall contention.
He abandoned in 2016 and 2017 and did not take part in 2018. Yet he emerged as one of the top contenders this year after riding flawlessly in the opening nine days.
He lost 1:40 because of a positioning error in crosswinds but made up for the lost time with impressive attacks in the Pyrenees, winning at top of the iconic Col du Tourmalet last Saturday.