David Walliams was the latest member of his team of celebrity cyclists to take a tumble as he struggled to climb the Lake District's Kirkstone Pass.
The comedian, who swam the English Channel four years ago, struggled to maintain momentum on the 1-in-4, 1,000ft climb and at one point went crashing to the ground. He pushed for a while before getting back in the saddle and making it to the top.
"It was so steep you just couldn't get the speed up to stay upright and I went over," he said. "It was a very tough route; a 1-in-4 gradient was incredibly hard to overcome."
Walliams' fall took place on the second night of his celebrity team's BT Sport Relief Million Pound Bike Ride. Fellow rider Fearne Cotton said the two days had been even tougher than her charity walk up Mount Kilimanjaro last year.
"Athletically I've never done anything like this; it feels harder than the Kili climb in that respect," the TV presenter said. "We're over half way now, but we are behind schedule so we all really need to kick on.”
Final team member Jimmy Carr arrived today to give the group a boost. After his stint in the saddle, the reality of the challenge finally hit home and he said: “My arse is currently like the flag of Japan!”
Davina McCall said: "No one remembered to tell Jimmy about the cream you need to put on your bits before you ride and I think he's red raw already!"
Walliams, Cotton, Kielty, McCall, Miranda Hart and Russell Howard began their 1,000-mile relay bike ride from John O’Groats to Land's End on Monday. They're aiming to make it to Land's End tomorrow and raise £1 million in the process. At time of writing they had passed the half way point and were just south of Manchester.
On the first night they battled through temperatures as low as -15°C as they made their way through the Highlands of Scotland. McCall said: "I'm so glad I managed to finish my leg. This is so many more times harder than I expected. The conditions were nothing short of brutal."
Former Olympian Professor Greg Whyte, who trained the team, said: "Riding in that kind of temperature at night poses serious risks – it's potentially deadly. No one would have batted an eyelid if they'd have said, 'let's call this off'. But they didn't and I'm amazed at how absolutely no one wants to let the team down."
Money raised will be spent by Comic Relief to help vulnerable people in the UK and in some of the world’s poorest countries. British Cycling are supporting the ride by providing insurance and encouraging their 30,000 members and staff to donate. To sponsor the team, go to www.sportrelief.com. You can follow their progress using the BBC's live tracker.