The race was won at the start when Webster slipped under pole-sitter Nathan Herne at the first corner.
From there he bolted into an unassailable lead, his margin blowing out to over five seconds at one point before it came back to 3.9s at the finish.
That finish was slightly earlier than expected, too, the race going time certain with four laps to go despite there being no safety car periods.
Things were tighter behind the runaway winner with Garry Rogers Motorsport teammates Herne and Aaron Cameron battling over second place throughout the race.
Despite Cameron's best efforts there was no way through Herne, the pair holding position to the finish.
Series leader Joey Mawson finished a conservative fourth place ahead of John Martin, Blake Purdie and James Golding.
Kaleb Ngatoa was eighth, Jordan Boys ninth and Tim Macrow 10th.
Tim Berryman sat out the race after a bizarre qualifying crash where he hit the wall on the front straight while warming his tyres.
