Natividad was actually tied with the Retanal brothers, Elim and William, who also finished the 7-round Swiss system competition with 6.0 points.
However, Natividad earned the right to claim the P2,000 champion's purse by virtue of a superior tie-break output with 26.0 points.
William finished second, while Elwin settled for third place honors.
Voltaire Sevillano copped the fourth place with 5.5 points. He is followed by Allan Salientes, Pedroza, Vonn Tidod, Eden Diano and Rodrigo Alejandro.
Venancio Loyola claimed the best scorer in the elementary division, while Kimberly Cuizon bagged the accolade in the distaff side.
Loyola and Cuizon pocketed P300 each for the feat.