"Its unfortunate it happened. Its a hard decision but we have to comply with the rules," said tournament chairman Taby Tabaniag, who declared the par-72 course unplayable and decided to cancel the first round, including the pro-am event upon approval of UBix president Bert Bravo.
Only four of 36 flights were able to finish their round before heavy rains, which lasted for almost two hours, rendered the 7,000-yard East course unplayable.
The second round starts at 7 today.
Former RP Open champion Robert Pactolerin took the early lead with a one-under par 71 before the rains and later thunderstorms forced the cancellation of the round. There were moves to stage the tournament at the nearby West course if the East remains soggy today.