Tadej Pogacar needed a last-ditch sprint to hang on to the Yellow Jersey on a crazy day of Tour de France of tractor rescue and the protesters blocking the route.
As Denmark's Magnus Cort Nielsen won stage 10 from Morzine to Megeve in a photo finish, the breakaway almost wiped out reigning champion Pogacar's 8min 43sec advantage and put Germany's Lennard Kamna in the overall lead.
But Pogacar's late dash was enough to preserve his custody of the fabled maillot jaune by just 11 seconds after two of his UAE Emirates team-mates, George Bennett and Rafal Majka, tested positive for Covid.
Bennett was forced to leave the race but Majka was allowed to continue as he was deemed not to be contagious, leaving Britain's Geraint Thomas to joke that his Ineos Grenadiers train avoided following the Pole's wheel.
The breakaway group's lead was more than seven minutes when protesters from the Derniere Renovation group - who also disrupted the French Open semi-final between Casper Ruud and Marin Cilic at Roland Garros - blocked the road with flares while also chaining themselves together around the neck.
After police dragged them aside, commissaires restarted the groups according to their time gaps, but the breakaway's advantage quickly went up to put Kamna in touching distance of yellow. He was only foiled by Pogacar's desperate surge up the steep airstrip at Megeve.
Noticeably, Pogacar did not ride with his team-mates until the final climb – but until his late burst it looked as if he had socially distanced himself from the leader's jersey.
Pogacar claimed afterwards the stage had been “no stress at all” but added: “It is not nice to lose team-mates, and I was sad to see George heading home. I hope to survive the next few days and we will keep fighting for the victory."
Cort Nielsen's victory on a gruelling 92-mile ride crowned a madcap day for his EF Education-EasyPost team, who had seen their bus get itself stuck at the stage start, blocking access for several other teams before it was freed by a tractor.
The Dane, who crumpled to the ground in a heap after his dramatic win, gasped: "It's unbelievable - I can't believe what just happened. I was on the limit for so long on this climb. For my type of rider, it can't be any bigger than this."
Earlier, QuickStep Alpha-Vinyl boss Patrick Lefevere all but confirmed that Mark Cavendish would be leaving the team at the end of the season.
Cavendish was denied the chance to break Belgian legend Eddy Merckx's record of 34 stage wins when he was left out of the QuickStep squad in favour of Fabio Jakobsen, who has won one of the first 10 stages.
Lefevere said: "He will not stay, I think not, it is not possible. It hurts my heart, I would like, but every now and then the time comes to say thank you for everything he has done for the team and I hope vice versa. I know that he wants to do two more years in the bunch... but he's not part of our project."
