With a strong wind against them, Snettisham went ahead when Mark Saintly broke the deadlock with a good header from a Mark Lloyd cross.
After the break, Snettisham settled down to play some good football.
Lloyd capped off his usual classy performance with a precise shot into the corner of the Thornham goal.
An inspired substitution saw Nathan Branch enter the fray and he promptly scored a fine individual goal.
Thornham goalkeeper Josh Hancock was kept busy and a terrific save from a Joe Green free-kick was one of many he was called upon to make.
Snettisham’s shotstopper Kieran O’Grady kept a clean sheet, thanks to his well organised defence and Scott Deadman picked up the man-of-the-match accolade.
Also worth a mention in dispatches was referee Ray Venemore, who kept a firm grip on a sometimes fiesty game.
n Turn to page 86 for the Lynn Sunday League round-up and the weekend’s football fixtures.