In a highly anticipated rematch, Demecillo suffered a knock-down in round two but came back strong to take home the vacant Bantamweight title with a technical knockout in round eight over compatriot Daryl Basadre.
23-year-old Demecillo, now 10-3-1 (7), stopped Basadre, 14-3-1 (10), in two rounds last June, and proved this time that the first win was no fluke.
In the co-featured bout, undefeated Rimar Metuda won the Asia Pacific Featherweight crown by stopping fellow Southpaw Jason Tinampay in round five.
Metuda, still only twenty years old but a pro for two years, won his first title and improved his professional mark to 8-0 (4), while Tinampay (21) falls to 6-2 (5).
On the undercard former WBF International Super Bantamweight Champion John Vincent Moralde remained undefeated, 14-0 (7), with a ten-round unanimous decision over Jerry Castroverde.