The Volkswagen driver was comfortably fastest on the two short tests, meaning he has now won eight of the 13 stages held on the event so far.
With Ogier increasingly out of reach, M-Sport team leader Ostberg will begin Saturday with an eye on Mikko Hirvonen's Citroen, just nine seconds behind in third place.
Thierry Neuville has now drifted away from the podium fight in fourth but still enjoys a comfortable gap back to the off-the-pace Dani Sordo in fifth place.
M-Sport has three of its Fords in the top six, with Nasser Al-Attiyah matching Sordo's times in sixth, ahead of Ken Block.
After his Friday morning drama, Chris Atkinson has now got back into the top 10 and has Martin Prokop and Benito Guerra next in his sights.
Evgeny Novikov is also making progress back up the order following his ECU issues and is now 12th.
Jari-Matti Latvala will restart from 22nd place for leg two, but will be nearly an hour behind with his Rally 2 penalties.
Leg one classification
1. Sebastien Ogier (France) Volkswagen 1:57:46.900
2. Mads Ostberg (Norway) Ford +00:33.000
3. Mikko Hirvonen (Finland) Citroen 00:42.000
4. Thierry Neuville (Belgium) Ford 01:07.100
5. Daniel Sordo (Spain) Citroen 02:40.100
6. Nasser Al-Attiyah (Qatar) Ford 03:24.100
7. Ken Block (U.S.) Mitsubishi 04:46.500
8. Benito Guerra (Mexico) Ford 06:03.400
9. Martin Prokop (Czech Republic) Ford 06:25.400
10. Chris Atkinson (Australia) Citroen 07:15.100