Loeb was in fine form in his Citroen on day one in Corsica

World champion Loeb won three of the four stages, with Gronholm taking the other, to establish a 19.9-second lead.

The two men - who have four world titles between them - are nearly a minute clear of their closest challenger, Alexander Bengue's Peugeot.

Gronholm's Ford team-mate Mikko Hirvonen was lying fourth.

We anticipated a beautiful battle and that's what happened Sebastien Loeb

Subaru's Petter Solberg, third in the championship behind Loeb and Gronholm, dented his hopes with an off-course moment on the first stage, and is more than three minutes off the lead.

Loeb's team-mate Dani Sordo, who suffered car problems in the first stage, climbed back up to fifth by the end of the day.

Loeb and Gronholm are turning the world title into a private battle - and it was replicated on the first day in Corsica.

"We anticipated a beautiful battle and that's what happened," said Loeb.

The pair were barely separable over the two morning stages, winning one each with Loeb holding a 4.9 second advantage.

But in the afternoon session, over the same course, Loeb won both stages and adding 15 further seconds to his lead.

"The car was not as precise as I had hoped because we had had too much pressure in the rear tyres and we have a small problem with the brakes," said Gronholm.

Standings after day one of the Rally of Corsica:

1. Sebastien Loeb (Fra) Citroen one hour 13 minutes 18.900 seconds
2. Marcus Groenholm (Fin) Ford +19.900 seconds
3. Alex Bengue (Fra) Peugeot 1:15.600
4. Mikko Hirvonen (Fin) Ford 01:23.400
5. Daniel Sordo (Spa) Citroen 01:36.600
6. Xavier Pons (Spa) Citroen 01:44.600
7. Jari-Matti Latvala (Fin) Ford 01:54.400
8. Nicolas Vouilloz (Fra) Peugeot 02:04.500