Mikko Hirvonen now needs a final stage miracle to win the World Rally Championship after he lost a minute on the penultimate stage with a loose hood.
The Finn had reduced Sebastien Loeb's lead to 18sec before the incident on the second run through Port Talbot, which meant the Ford had to continue with its hood missing.
"Just after the jump the pins came loose, and it's such high speed that the (t he hood)was getting lots of air underneath it," said Hirvonen. "On a long straight it came up and blocked the view completely so I had to stop and take it off."
He is now 1m25s behind Loeb with just SS14 remaining, and is only 0.9sec ahead of third-placed Dani Sordo in the second Citroen.
"Now we need a miracle but I'll try," said Hirvonen. "I've tried as hard as I could today."
Loeb was relieved to learn of Hirvonen's problem, particularly because he had been concerned by a poor response from his Citroen's turbo earlier in the day and by stones in the road on SS13.
"That's great news because I had to go flat-out again and now we can take it easier for the last one," said the Frenchman, who is now on the verge of a sixth consecutive title.