Strengths were evenly matched in the first 30 minutes of the match until table-toppers, Mioks, broke the ice with a Paul Wawa try.
A successful conversion ensured a 6-0 lead for them until Brendon Nima responded a few minutes later.
An unsuccessful conversion left the scores at 6-4 until a return from second half saw Mark Tony score the winning try for the Eastern Highlands side.
In front of a tightly-packed National Football Stadium, the Lahanis came from behind to claim the cup with a score of 10-6.