Tour de France: Even Bradley Wiggins finally accepts he's in touching distance of triumph

Emotional Londoner virtually guaranteed to be the first Briton to win Tour crown in 108 years

Bradley Wiggins' and Chris Froome's grip on the top two spots of the Tour de France tightened conclusively yesterday as the Sky team-mates dropped their most dangerous rival, Vincenzo Nibali, near the top of the 2012 race's final summit finish, thus virtually guaranteeing Great Britain's first ever outright Tour victory in 108 years.

Briefly losing contact with Froome within a few kilometres of the finish, the 32-year-old Wiggins said that he had dropped behind his team-mate because he was so overcome with pure emotion at the thought of what almost certainly awaits him in Paris in three days' time. "My concentration had gone, I knew it [the race] was pretty much over, for the first time in the whole race I thought I might have won the Tour," Wiggins said.

"When we rode away from Nibali and got to the last part... there were tears in my eyes as the realisation that the hard climbing was over sank in.

"All the fight in me just went out of the window. I was thinking of so many things; I allowed myself to drift."

Only the stage win, which was taken by Spain's Alejandro Valverde, remained outside the Britons' clutches as Froome, again showing he is the stronger climber of the two Sky leaders – a point that Wiggins conceded – slowed and glanced back repeatedly to ensure that the Londoner had all the support he needed to protect his top spot overall and was not in any danger of losing contact for good.

With his dream of winning the Tour now just a few days away from becoming reality, Wiggins said it was difficult on the ascent of the Peyragudes to stay on track mentally.

"Chris was egging me on, but I said to myself, 'That's the climbing done.' I'm not a born climber, I'm a time-triallist who can limit the gaps there. We knew Nibali was nailed, but I was in another world."

Finally, Wiggins seemed to resurface from his own thoughts and, for the last few kilometres, Froome faithfully fulfilled team orders and shepherded his leader to the line. Second just 20 seconds behind Valverde, Froome crossed the finish line with an emphatic nod, as if to say "job done", while Wiggins, in third, grinned from ear to ear as the prospect of becoming Britain's first Tour winner looms ever larger on the horizon.

Nibali's time loss of 18 seconds on the Briton as he crossed the line in seventh place was comparatively minor, and the Italian will almost certainly remain in third overall.

However, with no mountains left, any chance of the Liquigas rider winning the Tour is all but non-existent, and what was the last threat to Wiggins' yellow jersey, barring a crash or sudden illness, has now evaporated.

Although speculation will linger over what might have happened if Froome had been on another team, or if Alberto Contador and Andy Schleck – the two riders who have dominated stage racing for the past three years – had taken part in the 2012 race, Wiggins nevertheless brushed the issues aside. With Froome by his side as a team-mate – "it was one last thing to worry about" – and ultimately, he argued, it was irrelevant who else was present.

"My name will be on that list and that is all that matters. You can only beat who's turned up. Andy's had a lot of problems, other riders are out for other reasons," he said.

"Everybody has had to make sacrifices, Mark Cavendish has made them every day, and that's our job," Froome added when asked how hard it had been to work for Wiggins, rather than race for himself when perhaps he will never again have such a good chance to win the Tour. "It's difficult, but if you had told me I'd finish second in the Tour, I'd never have believed it."

Dave Brailsford, the team principal, ducked a question by French TV, though, over whether Sky's plan was to win the Tour with Wiggins rather than with Froome: "We have got the yellow jersey and done a great team job," he said.

On one of the toughest mountain stages of the race, not even Sky could be guaranteed a completely trouble-free ride, with Cavendish reporting that he had crashed at 3km from the finish line after a fan's flag wrapped in his handlebars. The world champion could complete the race, albeit second last and with his legs swollen from the impact of the fall.

After today's long, but probably very uneventful grind up through central France, all that remains for the two Sky riders is Saturday's 53 km time trial. Given Wiggins won the opening time trial in Besançon and Froome finished second, it would take a brave person to bet against the two Sky riders now.