At the start of the second of his four appearances in his World Rally Championship swansong year, Loeb set the pace by half a second for Citroen.
Volkswagen's Jari-Matti Latvala and Qatar M-Sport Ford driver Evgeny Novikov set equal second-fastest times, with Mikko Hirvonen and Mads Ostberg tied for fourth.
Qualifying pacesetter Sebastien Ogier was in a head-to-head with Loeb, but lost 2.5s in an impact with a snow bank.
Long-time stage leader Jarkko Nikara ended up eighth on his return with a Prodrive-prepared Mini, just ahead of the delayed Ogier.
Fellow returnees Henning Solberg and Matthew Wilson were 10th and 13th. Solberg did a late deal to use a spare M-Sport Ford, while Wilson is standing in for the unwell Nasser Al-Attiyah in the main Qatar M-Sport line-up.
After setting a sensational fourth-fastest time in qualifying, WRC Academy graduate Pontus Tidemand was 14th in his privately-entered Ford.