Kicking off Friday with a 16.7sec lead over Stéphane Lefebvre, Gryazin was immediately on the pace - posting the second-quickest time through the day's opening test, just 0.7sec down on Yohan Rossel.
But not just comfortable with conserving his lead, the 25-year-old upped the ante in his Fabia RS Rally2 to go fastest on the next four stages, only slowing down slightly in the day's final test to ensure a 29.7sec lead over Rossel when the field returned to Monte-Carlo.
Frenchman Rossel begun the day in third after losing around five seconds with a costly stall on Thursday evening, but he leapfrogged fellow Citroën C3 Rally2 pilot Lefebvre courtesy of his stage win on the day's opener. Lefebvre ended the day in third, 17sec down on Rossel and a further 46.7sec back from Gryazin.