However it was a short-lived pole, Mostert quickly slapped with a five-place grid penalty for Race 1 for speeding in pitlane during his session.
The penalty doesn’t affect the car’s pole position for Sunday’s race.
Mostert and Talbot will now start the opener from sixth, while Brendon Leitch, who was fifth fastest in the session, drops to 10th on the grid for an identical penalty to Mostert.
Valentino Astuti, who was 10th, will drop three spots for speeding while Black Wolf Motorsport Mercedes drops to the back of the grid after being hit with five spots for speeding.