Rivals believe start holds key to win

The long run from the grid to the tight Lisboa corner means that the second placed driver away from the grid has an advantage because he can benefit from the slipstream of the leader.

Duval proved the theory in the qualifying race on Saturday, when he dropped to second off the grid but was quickly able to retake the lead well before Lisboa. He went on to take a comfortable win.

And his closest challengers are adamant that they may be able to overhaul Duval if they get their tactics right for that crucial run down to Lisboa.

Robert Kubica, who finished second on Saturday, said: "I know that if you are first after the start then you will never be first into braking at Lisboa. Maybe tomorrow it will be better to not do a good start and then overtake him there."

Third placed finished Lucas di Grassi added: "For tomorrow I think the guy who turns into the first corner first does not arrive first into Lisboa.

"It will be important to have a good start and push more than I pushed today - and try and make our car as quick as the ASM at the beginning of the race."