Fryatt scored his goals in the 6th, 76th and 80th minutes, the 3rd goal a penalty after Peter Clarke's handball.
Fryatt has now scored 22 times this season, the first Leicester player to achieve 20 goals before Christmas since Derek Dougan over 40 years ago.
Leicester and Fryatt go in search of a 3rd consecutive hat trick, next weekend at Carlisle.