(CNN) -- Sebastien Loeb has clinched the world rally championship for the eighth straight year after closest rival Mikko Hirvonen was forced out of the Wales Rally GB Friday.
Hirvonen began the final round of the season trailing Frenchman Loeb by just eight points, but the Finn's hopes were ended when he spun off in his Ford Fiesta on stage seven and hit a buried tree stump.
Hirvonen had overtaken Citroen ace Loeb shortly before the accident which damaged his car's radiator.
He failed to return to a scheduled service stop and Ford team chief Malcolm Wilson later told the official website of world championship rallying that Hirvonen would not be able to continue.
"The engine is too badly damaged following a spin on stage seven which resulted in the radiator being damaged and subsequent driving with no coolant due to hole in the radiator," he said.
Loeb will go into the penultimate day's action on Saturday with a slender 1.1 second lead over Hirvonen's teammate Jari-Matti Latvala.
Another Ford driver, Norwegian Mads Ostberg, occupied third place but over a minute back.
The 37-year-old Loeb will be bidding for his 68th victory of his remarkable career, all with Citroen.
By claiming an eighth straight crown he has bettered the seven Formula One world titles won by Michael Schumacher.
But it has been one of the closest title battles in recent years, with Loeb fully extended by both Hirvonen and teammate and compatriot Sebastien Ogier, who went out earlier in the rally in Wales.