The Toksport WRT driver opened up a commanding 16.7sec advantage across Thursday night's 40.2 competitive kilometres in his Škoda Fabia RS Rally2, leaving a pair of Frenchmen trailing in his wake.
In what is the first WRC appearance for the all-new Fabia, Gryazin showed no signs of hesitancy at coming to grips with his new machinery. He won the opening stage by 7.9sec and the next by 8.6sec - steering clear of any trouble despite there being patches of black ice.
"It was not a big push," Gryazin said. "It was not slow but it was a well-managed pace - if I want to push more, I can do. A lot of things have changed since last year and maybe it's starting to work better. We will see over the next few days."
Citroën drivers Stéphane Lefebvre and Yohan Rossel rounded out the top three, with Rossel left ruing a costly stall at the start of SS1 which cost him around five seconds.
"I think I am just an amateur! I lost five seconds, I think," quipped the Frenchman at the end of the stage, insisting however that it could be recovered over the remainder of the weekend. Rossel sits 1.6sec down on Lefebvre.
Spanish up-and-comer Pepe López finished Thursday night with fourth position in his Hyundai i20 N. He ended 27.8sec down on Rossel, whilst former Rally1 driver Adrien Fourmaux rounded out the top five in an M-Sport Ford Fiesta Rally2.
Former European Rally Champion Chris Ingram, driving another Toksport-prepared Fabia, will begin Friday sixth overall, a further 6.4sec down on Fourmaux.
Finland
Italy
Hungary