Froome during 3rd stage of Dauphine Criterium Valmorel - Arabstoday Chris Froome laid down a Tour de France warning to his rivals as he climbed to victory and claimed the leader\'s yellow jersey on the fifth stage of the Criterium du Dauphine on Thursday. The Briton timed his attack to perfection at the end of the 139km ride from Gresy-sur-Aix to Valmorel to beat his main Tour rival, Alberto Contador, into second with American Matthew Busche third. Perhaps even more ominous for Froome\'s Tour rivals is that the Kenya-born rider, who was second on the Grand Boucle last year, claims he\'s still trying to find his form. \"From now until the Tour I hope to improve my form,\" he said. \"I\'m not yet at 100 percent, I\'m just where I want to be.\" The Sky rider took over from Australian Rohan Dennis in the leader\'s jersey with team-mate and another Australian Richie Porte moving into second overall. Overnight leader Dennis slipped to third overall as he lost almost a minute in the final 2km. Froome\'s victory was agony for Busche who was the last man standing from a 15-strong breakaway group that went clear within the first 10km. Busche looked capable of holding on for the win as he passed Belgian Tim Wellens, who had been the first breakaway rider to make a solo bid for home, in the final 5km. Alejandro Valverde broke out of the peloton to try to chase him down but made few inroads. Busche\'s lead was still hovering around the 20sec mark as he approached the final kilometre but Contador, hoping to make up for a poor time-trial showing the previous day, put in a devastating burst. That blew apart the remnants of the peloton, which by then was only about a dozen strong, but Froome stayed calm on Porte\'s wheel. And when the Sky leader finally counter-attacked, there was no stopping him. He reeled in Contador, who then tried to latch onto the Briton\'s wheel, before kicking again to overhaul Busche inside the final 200m. Froome finished four seconds ahead of Contador and now leads Porte by 52 seconds. Contador did look strong on the uphill finish, even though he could not quite match Froome. But the Briton believes it is too simple to assume the Tour will boil down to a straight fight between the pair. \"I can\'t say that, I don\'t know. In my opinion there will be more than two challengers for victory, I think more like six or seven. \"Sky is in a strong position, we have the advantage of having two of those riders (himself and Porte).\" Friday\'s sixth stage takes the riders over 143km from La Lechere to Grenoble before two mountain stages at the weekend.