The Norwegian (right) completed the 1.9km Karlstadt Super Special 0.8 seconds quicker than his reigning world champion team-mate Sebastian Ogier, who lost time by picking the wrong line in the early part of the test.
Ogier was a further 1.4s quicker than World Rally returnee Ott Tanak (Ford Fiesta RS).
The Estonian, starting his first event since the 2012 Rally of Spain, prevented Jari-Matti Latvala making a VW clean sweep of the top three by just 0.2s.
M-Sport Fiesta driver Mikko Hirvonen was fifth fastest, while fellow Fiesta driver Henning Solberg, starting his first WRC event since last year's Rally Sweden, rounded out the top six.
Hyundai drivers Juho Hanninen and Thierry Neuville sandwiched Citroen's Mads Ostberg, who finished the stage eighth quickest in his DS3.
Ostberg's Citroen team-mate Kris Meeke, who went off during yesterday's shakedown stage, completed the top 10.
Norwegian Anders Grondal was the star of WRC2, running first on the road in his Group N Subaru and leading the way until the faster WRC cars came through.
He wound up 13th overall, 0.2s clear of Jari Ketomaa's Fiesta and just two tenths adrift of ex-F1 star Robert Kubica's M-Sport Fiesta.