A Fistful of Conkers is inspired by the popular Spaghetti Western genre and is described as a classic tale of revenge, set against the backdrop of a school conker tournament.
Year 10 student Brandon Fletcher stars in the lead role as The Boy With No Name who has unfinished business with reigning conker champion One Eyed Jack, played by former Sixth Form student Max Marsh.
Max left Wales High last year and is now studying a degree in drama and performance at London’s South Bank University, and came back especially for the premiere.
And Devon plays school reporter Josie Wales who, desperate for a scoop, agrees to help the pair win the coveted Golden Conkers trophy.
Mr Day, who retired from Wales High in 2012, makes his screen debut as The Headteacher – a role which had the Savoy audience roaring with laughter.
The film will now be entered in to national and international film festivals.