On a difficult pitch, Port created the better chances throughout the match and Craig Dineley fired them in front with a curling strike into the top corner early in the first half.
The lively Sam Salisbury hit the woodwork with a lofted cross-cum-shot before Joe Crook saw his effort scrambled off the line.
Dineley added a second towards the end of the half, slotting home from close range after good work by Salisbury and Crook.
Kingsley struck the post midway through the second half but failed to threaten as Port�s defence stood firm.
With 15 minutes to go, Crook slid home after Dean Patefield headed Salisbury�s cross into his path.
Port retained possession to see out the game and Alan Benson put the gloss on the win as he charged down the goalkeeper�s clearance with his midriff to make it four.
Port coach Kris Donnell was delighted with the performance, singling out young defender Jayden Robinson for special mention.
�Jayden was tremendous, especially considering he played a full game for the reserves as well,� he said.
Port reserves went down 10-0 in a match to forget, with three players and coach Phil Smith all sent off.