(Writes through) By Julien Pretot SEMNOZ, France, July 20 (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. ... More...