Shepton skipper Jacob Sloggett put his side ahead in the twelfth minute but Jack Jones levelled the game up on 26 minutes with a low drilled finish. Mallet started with two former Hengrove players in Will Banks and Luco Ponsillo before bringing on a third, Dylan Gould, who fired home the winner with six minutes remaining.
Shepton go on to play Wincanton Town away in the next round of the competition.