Alex Olsen led rival Billy McConnell to the best lap in first practice as the FHO Racing with Kobelco rider clocked a 1min 27.589sec lap.
McConnell, who will battle with Olsen for championship runner-up honours this weekend, was just 0.265secs adrift of his rival with Dan Linfoot third Bjorn Estment fourth and Tom Ward fifth.
Pirelli National Superstock Championship with MotoNovo, Brands Hatch, FP1:
1. Alex Olsen (FHO Racing with Kobelco) 1min 27.589secs
2. Billy McConnell (C&L Fairburn Properties/Jackson Racing +0.265s
3. Dan Linfoot (Optimum Bikes Racing) +0.326s
4. Bjorn Estment (Specsavers Suzuki by Hawk Racing) +0.634s
5. Tom Ward (IN Competition/Aprilia) +0.688s