The Tour de France's visit to Yorkshire has been the "grandest" opening to the race in its history, according to the race's director who said five million may have watched the spectacle over the weekend.
Speaking after stage two finished in Sheffield, Christian Prudhomme said the huge crowds seen for the second day out on the route were "unbelievable, incredible, amazing, astonishing."
Organisers says they estimate the number of people who lined the route of the Grand Depart in Yorkshire this weekend at 2.5 million.
But Mr Prudhomme said: "I don't know. Perhaps in two days, perhaps five million, I don't know. It was unbelievable, unbelievable."
He said: "I t will stay as the grandest Grand Depart ever.
"Yesterday I was very, very impressed, I was delighted. But today, it was unbelievable, incredible, amazing, astonishing."
Today's 201km stage from York to Sheffield saw more scenes of crowds packing the roadsides following yesterday's events in Leeds, Harrogate and the Yorkshire Dales.
Perhaps the most dramatic were on the bleak moors of Holme Moss, above Huddersfield, where an estimated 60,000 cheered as the 197 remaining riders fought their way to the summit.
But there were similar scenes in other, normally quiet corners of Yorkshire, especially on the climbs which made today's stage one of the toughest opening days in Tour history.
On the roads near Bradfield and above Oughtibridge, north of Sheffield, and at Cragg Vale, near Halifax, thousands of people crammed on to the narrow lanes urging the riders on, only inches from their handlebars.
Today's stage started without British favourite Mark Cavendish who was forced out of the race following his dramatic crash yesterday.
"I'm absolutely devastated," Cavendish said before the start in York.
"I was in pain last night. I held a bit of optimism that it was maybe just swelling and would go down overnight, but it's actually worse this morning."
Cavendish came to grief almost within sight of the finish line in Harrogate - his mother's home town - giving yesterday's opening stage a dramatic climax.
This morning, thousands of people waved the riders off at York racecourse before the peloton made its way past the city's Minster and other famous landmarks.
A Lancaster bomber and a Spitfire saluted the arrival of the Tour with a flypast over the city.
Race organisers estimated that 100,000 people watched the race in York today.
By the time the riders reached the first of the stage's many challenging ascents, at Blubberhouses, between Harrogate and Skipton, the riders knew they were going to get the same frenzied reception they got when more than a million people turned out to watch yesterday's first stage.
At Holme Moss vast numbers of people stretched along the steep road and up the hillside on the northern side.
Many of those in the prime spots near the summit had camped nearby to get the best positions.
British Team Sky rider Geraint Thomas said: "It was unbelievable at times. Going up Holme Moss, I had goosebumps. It was amazing."
Sir Rodney Walker, chair of TdFHUB2014 Ltd, which organised the UK Grand Depart, said: "Around 2.5 million spectators lined the route over two days and revelled in being part of history. The passion of the crowds in Yorkshire has really made this a weekend to remember.
"There has been a huge amount of planning and hard work from all the partners involved to ensure the first two stages were a success.
"We have once again showcased how the UK can deliver amazing events and a world-wide audience has seen the best of Yorkshire, and the best of the UK.
"I have no doubts the benefits of hosting the Tour de France in the UK will be felt both in the short and long term."
Sir Rodney said: "When Gary Verity (chief executive of Welcome to Yorkshire) decided to bid and bring the event to Yorkshire, he did it to put Yorkshire on the world map.
"And he's certainly achieved that. I don't think there's any doubt about that.
"One of the questions I was asked very early on was how can you justify spending £27 million at a time of austerity.
"Well, of that £27 million, about 19 or 20 has been spent in Yorkshire and I personally think we've got that back already and with more to come, which will justify it as an investment, not a cost."
Mr Verity said: "When we first bid for the Grand Depart of the Tour de France, I promised Christian Prudhomme that we would deliver the grandest Grand Depart the Tour has ever seen.
"It gives me immense pride to say that we made good on that promise, and the success of this spectacular event will welcome an incredible new chapter in the history of Yorkshire.
"Millions of people both right here at the roadside and in homes all over the world have seen the magnificence of Yorkshire, and our beautiful county has done itself proud once again."
The economic impact of hosting the world's greatest cycling race has been conservatively estimated to be worth £100 million to the Yorkshire economy.
Mr Verity added: "We might have to revise those economic impact figures after the scenes we have witnessed this weekend. Undoubtedly, it will give a huge boost to the Yorkshire economy but it's the images of Yorkshire people, Yorkshire pride and Yorkshire's outstanding landscapes beamed around the world which have been simply priceless for the county."
Later, Mr Prudhomme added: "I work for the Tour, but I also love the Tour, and I have seen that the people of Yorkshire love the Tour too.
"I can see the Tour in their hearts, and in their eyes. For that, I say thank you to Welcome to Yorkshire, and to everyone in Yorkshire who has made this Grand Depart so very, very special.
"(Five-time Tour winner) Bernard Hinault said to me it is the first time in 40 years on a bike that he has seen crowds like we saw this weekend.
"What you did was good for Yorkshire, for sure, but what you did was also good for the Tour. When you said you would deliver the grandest Grand Depart it was the truth, you have raised the bar for all future hosts of the Tour de France."