Portugal's Rui Costa tackled the Col de Manse climb alone to win the 16th stage of the Tour de France yesterday. The Movistar rider broke away alone on the second-category climb near the end of the 168km stage from Vaison-la-Romaine and stayed ahead down the tricky descent into Gap to win by 42 seconds. Frenchman Christophe Riblon finished second and his compatriot Arnold Jeannesson was third. Briton Chris Froome retained the race leader's yellow jersey despite nearly coming off his bike as he battled with former champion Alberto Contador on the winding descent to the finish line. Contador came off on the same bend. Both men appeared unhurt but Froome accused the Spaniard of careless riding. "Alberto overcooked one of the corners and came off in front of me," Froome said. "I had to get round him and nearly came off myself - I had to unclip. "He is obviously getting desperate if he is attacking us on the descents. I just think it was careless riding." Froome, given great support by Australian Sky teammate Richie Porte, and Contador finished in a small group 11 minutes and eight seconds behind Costa, who also won a Tour stage in 2011. Contador, who won the race in 2007 and 2009, moved up to third in the overall standings, behind Dutch rider Bauke Mollema, ahead of today's time trial.