United back in front, before Fisher had claims for a penalty turned down when Ashley Wright looked to have been knocked over.
Then just to compound matters, Stone rubbed more salt in Fisher’s woes. United broke quickly and Stone wrapped things up with United’s third goal late on, following good work in the build-up by substitute Matt Day.
Earlier, Jason Goodchild and Kingwell both had chances inside the opening 20 minutes, the latter seeing his effort saved by Fisher goalkeeper Nic Taylor, who made one appearance for United last season as cover for George Kamurasi.
The United goalkeeper pulled off a fine double save, before Ryan Palmer and Dave Botterill tested Taylor.
Botterill missed out twice in the second half, putting both chances over the bar.
Kamurasi, Savage, Walker, Botterill, Avery, Kingwell, Palmer (Day 61 mins), Davisson, Stone, Goodchild (Stubbs 72 mins), Hill (Eldridge 81 mins). Subs not used: Welford, Vines.