SEMNOZ, France (Reuters) - As he was fighting gravity in the final climb of the Tour de France, Chris Froome lost focus and that was the moment the Briton realised he had his maiden grand Tour title virtually sewn up.
Colombia's Nairo Quintana was about to ride away to victory in the 20th stage and secure second place overall 5:03 behind the Team Sky rider, who finished third on the day at the end of a 125-km mountain trek from Annecy.
Spain's Joaquim Rodriguez jumped into a podium position after Alberto Contador, the 2007 and 2009 champion, slipped out of the top three when he cracked in the final ascent.
Dripping with sweat on the slopes of Semnoz, Contador dropped from second to fourth, 7:10 behind Froome going into Sunday's final stage - a festive parade from Versailles to Paris with only the final sprint being contested.
"It was quite an overwhelming feeling, with just over two kilometres to go, when I was with Quintana and Rodriguez," Froome told a news conference.
"I thought 'I've got five minutes, this is pretty much wrapped up now, this is it now, I'm here and nothing is going wrong'.
"There were different obstacles each day but getting at that point it became hard to concentrate."
Barring a crash, Team Sky's Froome will succeed compatriot and team mate Bradley Wiggins, who missed this year's race because of a knee injury.
Showing little emotion, Froome hinted at his relief to have his first grand Tour almost in the bag.
"It is difficult for me to put it into words. It has been an amazing journey for me," the 28-year-old Kenya-born Froome said.
"The race has been a fight every single day with crosswinds, rain, mountains, good days in the mountains, bad days in the mountains, the team has come under pressure."
Slovakian Peter Sagan is set to retain the green jersey after opening an unassailable lead in the points classification over Mark Cavendish, who will look to claim his fifth straight win on the Champs-Elysées on Sunday.
On his Tour debut, Quintana is also about to secure the white jersey for the best Under-25 rider as well as the polka-dot jersey for the best climber.
"I can't ask for more. I almost have everything, it's fantastic. Thank you to my team mates and my sports directors, who have helped me achieve this," Colombia's first stage winner since Mauricio Soler in 2007 told reporters.
Quintana, 23, of the Movistar team sped away with one kilometre left in the final climb, dropping Froome who had earlier shaken up a group of favourites with a trademark attack - rooted to his saddle, jutting elbows and nodding head.
Froome was then overtaken by Rodriguez, who had worked hard in front of Quintana and the Briton in the final kilometres to distance Contador and become the second rider to feature on all grand Tours podiums without winning any of them.
Froome joined the slick Team Sky unit in 2010, where manager Dave Brailsford began grooming him into a grand Tour rider.
In 2011, he finished second overall in the Vuelta, having worked for team leader Wiggins.
Last year, Froome looked capable of contending for the title on the Tour but he was still Wiggins's lieutenant.
Now having tasted victory, it appears Froome is hungry for more.
"I'm 28 and I'd like to come back and keep contending for the Tour as long as I can and as long as I have the motivation," he said.
His rival Contador also plans to stick around.
"Tomorrow the 2013 Tour ends, but the 2014 Tour starts," said Contador, who will at least celebrate Saxo-Tinkoff's victory in the team classification. (Editing by Alison Wildey)