Cebu City’s Grace Quintanilla was 13th, a stroke back from Gaccion, while Reese Ng was T15, three shots further.
Serdenia, who shot to fame over his humble beginnings, was six-over in the tournament and finished tied for 14th.
Geoffrey Tan was three shots further for a share of 18th place, while Shinichi Suzuki was T21 after a 11-over total.
Thailand’s Boonsernor Teerwut bagged the Boys’ title finishing at 10-under and winning by two shots over South Korea’s An Senonghyeon.
Philippines Team 2, powered by Serdenia and Quintanilla, finished tied for 12th in the team competitions. Philippines Team 3, composed of Tan and Gaccion, was 15th. Suzuki and Ng’s Philippines Team 1 was 20th.