A collision with a rock on an icy surface has dented rally great Sebastien Loeb's hopes of an eighth Monte Carlo Rally title, after his Citroen suffered a broken rear suspension.
The nine-time world champion, who had led overnight as well as at the midway stage on Friday, lost around six minutes after the accident on the day's final run.
That allowed two-time defending world champion Sebastien Ogier to overturn a 41-second deficit to snatch the lead.
The Volkswagen driver now has a one minute and 45 second advantage over team-mate Jari-Matti Latvala with another Volkswagen pilot Andreas Mikkelsen in third spot.
Loeb is racing in the world championship for the first time in 15 months and his run for Citroen in Monte Carlo is his only scheduled appearance of the 2015 season.
The 40-year-old triumphed in the wintry conditions of the Principality seven times between 2003 and 2013.
Friday proved a black day all round for Citroen as Loeb's Irish teammate Kris Meeke also suffered damaged suspension.
Poland's former Formula One star Robert Kubica, who had picked up a 10-minute penalty on Thursday, crashed his Ford Fiesta, damaging the front and losing another three minutes.