The win saw Guernsey move up to second in the league
Guernsey moved up two places to second in London 2 South West after hammering London South Africa 48-3.
Captain Simon Sharrott said: "From the very first minute we played with the intent to win.
"The basic errors were not there this week, the boys really stepped up a gear. It could have been 60 or 70."
That win, combined with away defeats for Guildford and London Cornish, saw the Sarnians move to within two points of league leaders Tottonians.
Guernsey are one of four clubs locked on 14 points and lead Guildford, London Irish Amateur and London Cornish on points difference.
They now travel to Tottonians on Saturday in their last game of the year and Sharrott added: "Hopefully we can create a good performance and get those two points, as that will keep pressure on at the top of the league."