Villiran struck in the 10th, 22nd and 31st minutes to propel the hosts to the lopsided triumph.
Other Negros Occidental scorers were Elvin Marcellana (55th and 62nd minutes), Khey Salazar (53rd), Jason Costanilla (70th) and Jose Mari Gabalfin(75th).
Powerhouse NCR-Air Force led the other opening-day winners Sunday in the tourney organized by the Philippine Football Federation and supported by the Philippine Sports Commission and Congressmen Monico Puentevella and Charlie Cojuangco, who is also NOFA (Negros Occidental Football Association) president.
The NCR-PAF booters blasted Rizal province, 10-0.
In other matches, Iloilo beat Cagayan de Oro—WG&A/Samsung, 3-1; Negros Oriental topped Davao, 3-1; Cebu and Masbate won over Baguio and Iligan, respectively, both by default.
Negros Occidental Vice Governor Isidro P. Zayco, Mayor Luzviminda Valdez, Congressmen Puentevella and Genaro Alvarez, PSC Chairman Eric Buhain and PFF president Rene Adad graced the opening ceremony.