Raiders took firm control of the game in the first half as they opened up a 33-7 lead thanks to tries from Anthony Armstrong, Callum Roberts, Iwan Shenton, Ethan Smith and Ciaran McGann.
The hosts staged a second-half fightback, but a Michael Cantle try helped ensure the visitors held on to a lead.
The win leaves Guernsey third in the table on points difference, with Old Albanian - who come to Footes Lane for a 5pm kick-off next Saturday - and leaders Oundle also four from four so far.
Jersey sit bottom and are still looking for a first win on their return to level four of English rugby after drawing 31-31 at Henley this weekend.
Elsewhere, Guernsey Raiders Second XV also won a high-scoring game on the road, beating Tottonians Seconds 45-41, while Guernsey Raiders Women lost an entertaining match 39-29 to Worthing.
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