He was followed to the try-line by hooker Ross Bloomfield, his first try in senior rugby, and centres Rhys Jones and Steve Phillips. The four tries and a conversion and two penalties from the boot of skipper, outside-half Matthew Owen provided 28 points to Tonna's solitary score in reply, a try from Nick Thomas.
The second half was a more even affair in terms of points scored, with Phillips grabbing his second after the break, converted by Owen for 35-5 before Jason Evans snatched back a try for the visitors for 35-10.
Tonna's unwillingness to go down without a fight brought a fleeting ray of hope as Ryan Freeman grabbed their third unconverted try for 35-15 but it was all to little effect as home lock Richard Hnyda snapped up a deserved try, which was just reward for his work-rate in both tight and loose. Owen couldn't convert but 40-15 was a just reflection of the Seaweeds control throughout the match.
Prop Ben Price gave his opposite number a torrid time at the scrums, whilst Lloyd Long was again outstanding at his all-round game. Player coach Mat Roberts kept everything ticking over at scrum-half before giving way to Gareth Edwards, whilst substitute lock Ian O'Keefe produced the tackle of the season leaving his opposite number wondering what time of day it was.
Coach Blair Driscoll is seeing his side take good shape now and a week's rest will give a welcome respite after a great opening month. That said, no-one is taking next opponents Blaengarw for granted as Porthcawl head north up the valley on Saturday 06 October.