An entertaining evening saw the visitors open the scoring when Rhys Jordan low effort found the back of the net after a quarter of an hour.
A commanding Casuals emerged after the break and three goals in the first 18 minutes of the second period had turned match around.
Dave Hodges superb effort from 20 yards brought the game level (52) and two quick goals from Jamie Byatt (60) and Steve Goddard (63) - pictured scoring above, ensured Casuals first ever victory over the Channel Islanders.
Jamie Byatt had two further efforts disallowed for offside - pictured below, as Casuals domination was complete.
A full match report can be viewed here