Pesda took a 2nd minute lead when a free kick from the right flank was misjudged by Denbigh custodian Arwel Hughes and the ball rebounded off the near post for veteran Lee Dixon to score from a tight angle.
Denbigh recovered their composure and dominated the rest of the first half and where denied an equaliser by 2 quality saves and a goal line clearance.
However Denbigh made the breakthrough when good approach play by Ian Evans and then a spectacular over head kick by Stu Vernon resulted in Kristian Pierce scoring with a low right foot shot into the bottom left hand corner.
Denbigh continued to dominate the 2nd half and were rewarded with a penalty when Mark Roberts was brought to ground by the visiting custodian who saw yellow for his effort.
17 year old Kristian Pierce stepped up to convert the resulting penalty with consummate ease. Ian Evans scored with a rare headed effort before the 10 man Bethesda gained an 89th minute consolation through Neil Hughes.