Police said Armando Lucido, 54, and his driver, Nestor Pamplona, 42, were cruising Barangay Sambat on board a Mitsubishi L-300 van when they were waylaid at about 7:30 p.m.
The ambushers were riding in a Mitsubishi Lancer which was later found abandoned in Barangay Darasa.
Lucido sustained 10 gunshot wounds, including one in the head, while Pamplona had 11, two of which pierced his right kidney and liver.
Police found 63 empty Armalite shells at the crime scene.
Probers still have no clues on the ambush-killing, but suspect that Lucidos rivals in his alleged illegal activities had something to do with it. Rene Alviar, Arnell Ozaeta and Christina Mendez