Mark Cavendish was "gutted" tonight after his dramatic crash denied British fans a fairytale finish as the world's greatest bike race returned to the UK.
The star fell heavily in the final sprint to the line as the first stage of the Tour de France came to a close after a day that saw much of the country gripped by cycling fever.
Cavendis h was left prone on the ground clutching his shoulder after colliding with fellow competitor Simon Gerrans near the finishing line in Harrogate - his mother Adele Towns's hometown.
Medical examinations indicate that he injured the acromioclavicular (AC) joint between his right shoulder and collarbone. His team Omega Pharma-QuickStep said a decision about whether he will take part in the next stage tomorrow will be taken in the morning.
The Isle of Man rider tonight apologised to supporters keen to see a British rider over the finishing line first after the iconic race crossed the Channel for the first time since 2007.
"I'm gutted about the crash today," the 29-year-old said.
"It was my fault. I'll personally apologise to Simon Gerrans as soon as I get the chance. In reality, I tried to find a gap that wasn't really there.
"I wanted to win today, I felt really strong and in a great position to contest the sprint thanks to the unbelievable efforts of my team. Sorry to all the fans that came out to support - it was truly incredible."
It was an unfortunate climax to a day that saw Britain give a rousing welcome to the world's greatest cyclists, with the Duke and Duchess of Cambridge and Prince Harry among more than one million spectators who turned out for the Grand Depart of the 101st Tour.
After the announcement of Cavendish's crash, Kate put her hands to her mouth and leant over the barrier to try to get a glimpse of the accident site 200 metres further down the road.
The thousands of people watching with her at the finish also gasped in unison when they realised he had gone down.
Cavendish limped back a few minutes later, passing right in front of the royal enclosure. William, Kate and Harry again looked shocked as they could clearly see his torn shirt and injured left arm and shoulder just a metre in front of them.
Only half an hour before, the royal trio had been chatting to Cavendish's mother who was a guest in the royal area.
She described how she was "speechless" and "honoured" after meeting the royals, describing them as "lovely, lovely, lovely people".
She added: "They said they've started watching cycling now and they love it."
Prime Minister David Cameron was among those engrossed in the action.
He wrote on Twitter: "What a dramatic finish to stage 1 of the Tour, sadly it wasn't Mark Cavendish's day.
"Yorkshire has done the UK proud today though, and we look forward to more tomorrow."
More than a million people lined the streets of Yorkshire amid jubilant scenes as crowds flocked from all over the country to get a glimpse of the 198 racers passing through the county's striking scenery.
Kate, w earing a bottle green Erdem coat over a green Suzannah dress and carrying a grey clutch purse, cut the ribbon to officially start the 190.5km stage in Leeds.
Organisers said "well over" a million people watched along the route, with initial estimates suggesting there were 230,000 spectators in the centre of Leeds and more than 10,000 watched the riders on the steep climb at Buttertubs Hill.
Sir Rodney Walker, chairman of co-ordinators TdFHUB2014 Ltd, said: "Spectators have had a fantastic day they will never forget and Yorkshire has been showcased to a massive global audience.
"It has taken a huge amount of planning and teamwork, so thank you to all of our partners, and especially our stewards and the Tour Maker volunteers for all of their hard work.
"Today has set the tone for the next two days, and we look forward to seeing more huge crowds lining the route to watch the world's best cyclists in action."
Two spectators were hurt as the action unfolded.
Police said a teenage boy was in a stable condition after he was airlifted to hospital with leg injuries after what police described as "a team vehicle which formed part of the Tour de France convoy" hit the youngster.
Meanwhile a woman was also flown to hospital with head injuries after falling through a roof while watching the race.
The intense interest in the event put a strain on local transport links, with delays and large crowds at Leeds and York stations in the afternoon as thousands tried to make it to Harrogate for the finish of the 190.5km stage.
Long queues developed at Harrogate railway station tonight as the massive crowds who packed into the town tried to leave.
All road routes in the area were also heavily congested as tens of thousands of people went home.
There was a carnival atmosphere in the town centre, with its many bars, cafes and restaurants all packed to the point that people spilled out into the streets.
The stage was won by German Marcel Kittel, who received the yellow jersey from Kate.
Defending champion and British hopeful Chris Froome finished sixth.