Burns slipped off the road and flattened his exhaust pipe, forcing him to complete special stage three with vastly reduced power.

Burns said: "It was my mistake, pure and simple. I braked too late on a fast downhill section and slid backwards into a bank, bogging the car down to its axle.

"Now I have to fight back. I am confident I can still do well."

Burns' car was repaired before stage four - but, after that run was cancelled, he lost more time to Gronholm on stages five and six and ended the day's serious running two minutes behind in eighth place.

Burns' mistake under pressure has almost certainly ended what was considered one of the few chances of Gronholm facing any opposition on the rally.

It was reminiscent of an incident on the Rally of New Zealand in October, when Burns made a mistake while trying to defend his lead from Gronholm.

It is a bitter blow to Burns, who had been determined to win his home event after being outclassed by Gronholm all season.

The Finn won his second world championship with two events to go, while Burns has yet to win a single rally in a year he started as world champion.

Burns was not the only British hope to make a potentially disastrous error early on day two.

Colin McRae, the only other driver considered capable of challenging Gronholm in Wales, also made a mistake on Friday morning.