Belgian Thierry Neuville, third in the championship for Hyundai, also had a difficult day on the Mediterranean island and finished the leg seventh overall after running into a ditch in the afternoon.
Ogier led the championship standings going in to Sardinia, two points clear of Toyota's Estonian Ott Tanak with Neuville a further eight points adrift.
Tanak was best placed of the title contenders, ending the leg in third place and 11.2 seconds off the pace with every chance of taking the lead on Saturday.
The day's seventh stage was cancelled after a spectator required medical attention, with a nominal time awarded since the top three had already gone through.
Five different drivers led over the course of Friday, including Toyota's Jari-Matti Latvala who later rolled his car and continued without a windscreen -- even winning a stage -- before retiring in the afternoon.
Saturday is the longest leg, with stages to the east of Alghero.
(Reporting by Alan Baldwin in London, editing by Pritha Sarkar/Nick Mulvenney)
