Navrin won the first race of the 85/150cc nine to under-12s and took the next two seconds, leaving him to take the round win, while fellow local Regan Duffy won those next two races to come second overall.
Navrin also came fourth for the round when he later competed in the 65cc 10 to under-13s, which was won by Duffy who took all three wins.
Meanwhile, brother Caleb also had the clean sweep of the 85/150cc 12 to under-14s as did fellow local lad Jake Pruiti in the 128-150cc/250cc 15 years.
Other round winners included Stuart Eardley-Wilmot (128-150cc/250cc 13 to under-15), Jaden Tate (85/150cc 14 to under-16), Tylar Solomon (50cc seven to under-nine), Connor Teirney (combined 100/125cc 13 to under-15 and 15 years) and Jasyn Roney (65cc seven to under-10s).
Round three will be held at Hendley Park, Byford on June 16.