Matt Truelove emerged quickest of the Superstock riders this morning, as the TAG Racing Honda rider clocked a 52.565s lap in the rain.
Second quickest and 0.210secs adrift of Truelove was Declan Connell, as Ash Beech rounded out the top three in the opening session.
Local hero Lewis Rollo was fourth at the chequered flag with Simon Reid fifth.
Pirelli National Superstock Championship, FP1:
1. Matt Truelove (TAG Racing Honda) 52.565s
2. Declan Connell (Rapid Honda with Drivelife) +0.210s
3. Ash Beech (Jones Dorling Racing) +0.490s
4. Lewis Rollo (Motorrad Central Edinburgh by MLav Racing) +0.538s
5. Simon Reid (Carl Cox BMW by MLav Racing) +0.603