Kyle Devenish continued his good run of form by scoring twice after St Peter team-mate Jake Prince had put the hosts ahead in an eventual 3-1 success.
Jersey could have had the game wrapped up at half-time, but only managed to achieve that as the final whistle approached – after Guernsey’s Ben Bullock had reduced the deficit.
The visitors had chances to level the scores, but were caught short at the back with four minutes remaining and conceded a third goal.
Full report and reaction in Monday’s JEP.