Cadets took control from the start of their turn at bat and were easily ahead of the required run rate from the first couple of overs. Cadets all-rounder Donavan Deeble set up the victory with a quick-fire 44, with skipper Scott Steward posting an unbeaten 35.
Victory came in the 11th over with eight wickets to spare.
Earlier in the day, during the final round before the finals, Central had a great battle with fellow Rotorua team Bay of Plenty Indian Sports.
Central reached 123/8, Graeme Whiles top-scoring with 38 runs, while GS Gargan and LS Bhatti took four wickets apiece for the Indian side.
The match went down to the wire, with Indian Sports needing 10 runs from the last over to deny Central a berth in the final but line-and-length bowling allowed them just four runs.
-Lonestar Baywide T20 grand final:
Bayleys Central 104/8 (Ryan Pedley 33; Ben Christensen 3/19, James Birchall 2/29) lost to Cadets 106/2 (Donovan Deeble 44, Scott Steward 35no)