Tour is not a two-horse race, says Vincenzo Nibali

The Astana rider opened up a lead of one minute and 44 seconds over team-mate Jakob Fuglsang with a third-placed finish on the first mountain stage of this year's event on Saturday, coming in three seconds behind Tinkoff-Saxo's Contador in difficult conditions.

Following the withdrawal of Chris Froome through injury earlier in the week, the duo are now the overwhelming favourites to top the general classification, with Nibali currently two minutes and 34 seconds clear of sixth-placed Contador.

However, while acknowledging the challenge of the Spanaird, Nibali believes the likes of Richie Porte (Team Sky) and Alejandro Valverde (Movistar), third and fifth in the general classification respectively, could challenge for the yellow jersey.

"He's [Contador] ready to gain time wherever he can," he said. "I've tried to handle the situation the best way I could. I've tried to control until the very end. I've resisted to all of his attacks.

"The race is not a duel, though. It's more than that.

"Richie Porte is up there. He was supposed to be the last man for Froome. He's not here by coincidence.

"I've also seen Valverde riding at ease even if he lost a bit at the end.

"There have been great riders in action. I feel good despite the rain. I try to remain calm in all occasions."

Victory on stage eight went to Ag2r-La Mondiale's Blel Kadri, who also claimed the polka-dot jersey.