A Dutch fan filmed the mishap during the UCI Road World Championships.
Torrential downpours hit the course on Tuesday morning, and Danish rider Johan Price-Pejtersen can be seen approaching a flooded road junction before finding the water deeper than expected and falling off his bike.
The bad weather also forced the closure of the Harrogate Fan Zone today.
The UCI races are in Yorkshire from September 21-29.
Andy Hindley: What the UCI races will mean for cycling in YorkshireHuge crowds have been gathering in the main host town of Harrogate for the event.
The route passes through the Yorkshire Dales National Park and several towns and cities, including Skipton, Beverley, Leeds and Bradford.
The region was also the first ever to host a mixed relay time trial event.
UCI Road World Championships: What the fans in Harrogate thought
Local fan Paul Halliday, 47, was by the race barriers in a poncho with son Macauley, six, and brother Mark and his wife, Nicole.
The chartered surveyor, whose group had a stuffed sheep mascot held up high with them, said: “It’s amazing - for the town and Yorkshire.
“The world is coming here. You can’t beat this publicity.”
“You have to hope the weather holds, but it’s not diminished the crowds. The whole thing’s awesome.”
Gallery: All the photos from the first days of the UCI Road World Championships in HarrogateMr Halliday said that he was “really proud” to have the races come to town.
“It’s just getting the passion going, getting the crowd going.
“Once you have got a taste of it, you want it to come back again.”
Fellow Harrogate resident Edwina Barwick, 69, said “it’s been huge at the other events we’ve had,” acknowledging the weather’s role.
“I think it’s brilliant but there’s an awful lot of negativity with the residents, I’m afraid, because of the road closures.”
Her friends from Wellington, New Zealand, Graeme Orchard and Esther Scammell, who came to Harrogate on a trip to Europe, were impressed with the event.
Mr Orchard said: “For us, it’s a really nice town centre and a really beautiful place to have it.”
The championships also proved popular among regional cycling groups, who rode out in spandex to get close to the sport.
Martin Clough, 54, from Woodlesford in Leeds, is a member of the Seacroft Wheelers and has been riding for around 20 years.
“With the Tour de France, people got the knack of that but I don’t think they quite get the gist of how big this is,” he said.
“I know some of the residents are up against it a lot but to appreciate what’s going on, it’s amazing.”
Again, the wet conditions were no barrier to his enjoyment.
“You can’t be a fair weather cyclist in Yorkshire,” he said.
Chris and Annette Jones made the trip from Birmingham and are due to stay for the full week.
The couple rode to Harrogate town centre yesterday on a tandem from their caravan site at Esholt.
Mr Jones, who along with his wife wore the attire of the Birmingham Midland Cycling club, said: “We’re here for the week, for everything.
“This is an area we’ve never been to, we’ve never been to Harrogate.”
They have made trips to the region for the Tour de France in 2014 and for the subsequent Tour de Yorkshire competition around the county and made reference to the terrain, joking that
they would need an electric tandem to tackle the inclines in the area.
“Coming from Birmingham as we do, we don’t really know about hills,” he said.