Russian Denis Menchov's hopes of winning the Tour de France suffered a blow when he lost ground in the 16th stage, a 157-km mountain ride won by Frenchman Cyril Dessel on Tuesday. Rabobank's Menchov was dropped by the other favorites on the descent of the Cime de la Bonette-Restefond, the roof of the Tour at 2,802 meters, and lost 35 seconds to his rivals. He dropped down to fifth place overall, 63 seconds behind the leader. Frank Schleck of Luxembourg retained the overall leader's yellow jersey and leads Austrian Bernhard Kohl by seven seconds and Australian Cadel Evans by eight. AG2r-La Mondiale rider Dessel beat compatriot Sandy Casar of the Francaise des Jeux with Spain's David Arroyo of the Caisse d'Epargne team in third. “Little by little, in the ascent to La Bonette, I started to believe in victory,” said Dessel. “At the beginning I was working for my leader, Tadej Valjavec, because we wanted to catch (Stefan) Schumacher. But then I took my chance in the downhill.” American Christian Vande Velde, who started the stage fifth overall, lost all hope when he tired badly and trailed home with a 4:03 deficit. France's Samuel Dumoulin, Thomas Voeckler and Christophe Le Mevel, with Belgian Sebastien Rosseler and German Schumacher, broke away after 40 km. South African John-Lee Augustyn hit the top first but crashed on the descent and as his bike went down the mountain, the Barloworld rider was helped back up by a spectator.