Saint-Etienne: Tour de France leader Vincenzo Nibali admitted he is wary of the apparent calm that has settled around his lead in the Grand Boucle.
Friday sees the peloton head into the Alps with a 197.5km 13th stage from Saint-Etienne to Chamrousse, including two brutal climbs at the end.
Nibali has been comfortably in control of the Tour since taking the leader`s yellow jersey on the second stage with a daring solo escape.
He lost it last Sunday to Frenchman Tony Gallopin, but only for 24 hours before his victory on Monday`s tough mountainous stage saw him don the jersey once again.
The Sicilian leads Australian Richie Porte by 2min 23sec with Alejandro Valverde of Spain third at 2:47.
But although he has not lost a single second to any of his overall rivals on any stage, Nibali says he cannot afford to take his eye off the ball ahead of the next two Alpine stages.
"There are still a lot of stages left to the end and we all know that every day there can be another surprise," he said.
"There are top class rivals such as Porte and Valverde who are the closest.
"We (Astana) have to stay calm and tranquil and try to manage the situation.
"It is often when things seem simple that they can be most difficult.
"But I`m calm because I have a solid team and until now we`ve managed the race well."
Some have suggested it is now a race to see who will finish second behind Nibali, with young French pair Romain Bardet and Thibaut Pinot well placed in fourth and sixth respectively to give the host country a spot on the final podium.
But Nibali dismisses any notion that he will simply be left to ride off unmolested to Paris with the yellow jersey safely tucked away in his possession.
"We can expect attacks from other teams, they won`t wait and watch and think of securing a (good finishing) position," said the 29-year-old.
"There are riders like Valverde who have come here to finish high up. Also Richie Porte."
Porte suggested he would be more likely to make his move on Saturday`s 14th stage, a 177km trek from Grenoble to Risoul with two first category climbs and one uncategorised one, the Col d`Izoard -- the highest point of this year`s race at 2,360m above sea level.
But the 29-year-old Team Sky leader said any rider needs to be ready to pounce on any opportunity to put time into his rivals.
"Every day, if you stay at the front there`s your opportunity," he said.
"The way this race has gone, certainly if you look more towards a stage like Risoul, I know that climb quite well.
"There are opportunities everywhere, somebody`s got to have a bad day somewhere and I think that`s where we`re ready to go."
Certainly, Nibali is more worried about that finish in Risoul than Friday`s.
"I haven`t done reconnaissance at these climbs. The one I fear more is the second stage because the first day you have more energy but the second requires more effort and takes more out of you.
"We will try to manage it with the team, we`ve had good days and we`ll try to control things.
"It won`t be easy for sure, people will attack me but I`ll try to defend the yellow jersey and if I can take some seconds, I will try that."
Even so, the 13th stage cannot be underestimated as it ends with a first category ascent and then the uncategorised summit finish.
There are 138km before the 14.1km first category Col de Palaquit climb with an average gradient of 6.1 percent.
What makes that climb particularly difficult is the frequent changes in steepness ranging from 3 percent to 11.7 percent.
The hors category climb to Chamrousse is 18.2km long with a brutal 7.3 percent average but more consistent in its difficulty, although first half is slightly tougher.