Vincenzo Nibali tightened his grip on the 2014 Tour de France by riding away to his third stage victory on the 197.5km, 13th stage from Saint-Etienne to Chamrousse on Friday. Nibali attacked 6.6km from home and put almost a minute into nearest rival Alejandro Valverde, who finished fourth on the stage but moved up to second overall. Pole Rafal Majka was second on the stage with Czech Leopold Konig third while Australian Richie Porte, who started the stage second overall, cracked on the final climb to drop down the order. Nibali proved he is simply too strong for the rest on a day when his Astana team looked vulnerable, with chief lieutenant Jakob Fuglsang crashing on a descent and Michele Scarponi struggling and dropping away on the penultimate climb. But the Italian didn’t need anyone, responding first to an attack by Valverde on the final uncategorised climb and then riding away from the Spaniard. He caught Majka and Konig before leaving them in his wake in the final 3km to win by 10sec. Valverde came in 50sec after the 29-year-old to drop to 3:37 behind the leader. Young Frenchman Romain Bardet moved up to third at 4:24 after finishing the stage seventh, just 1:23 behind Nibali. It allowed him to keep hold of the young rider’s white jersey ahead of Thibaut Pinot, who is up to fourth at 4:40. But the big loser was Porte who came over the line almost nine minutes after Nibali and dropped right out of the top 10, now more than 11 minutes off the pace.