The 26-year-old, who topped the podium at the 2016 World Championships in Igls, Austria, holds a 0.35-second advantage following the opening two heats in Canada.
Germany's Hermann, who took silver in Koenigssee in 2017 but has twice won team gold, clocked in with an overall time of 1:46.65 to top the leaderboard.
She will however face tough competition from countrywoman Jacqueline Loelling, the defending champion, who lies second in 1:47.00.
Unerring Friedrich clinches 11th world title
Hermann leads Germany to relay triumph
And an all-German top three was completed by Sophia Griebel (1:47.47), teeing things up nicely for Friday's third and fourth runs.
Friedrich on top at halfway mark of four-man World Championships
Friedrich makes it six in a row in Altenberg