The home side crossed through Callum Gleadall and Lewis Davies, and doubles from Connor Lewis and Kian Godwin maintained Blackwoods' squeaky-clean record this season.
Risca fought back through Jack Hale and a double from Kane Blair to remain winless this season.
The hosts lit up Glan Yr Afon Park just eight minutes into the game when Connor Lewis raced down the wing to dive over under the uprights giving his side a lead of 7-0 early on.
It wasn't long before the visitors were level when Blair sniped his way through a ruck from 5 meters out to bring the scores back to deadlock.
The visitors incredibly grabbed the lead when Blair grabbed his second breaking through the Blackwood defensive maul to touchdown and slam his side into the lead.
Gleadall closed the gap with a penalty from just outside the Risca 22 bringing the scores to 12-10 in favour of Risca.
It wasn't long before the hosts were back in front when Lewis smashed his way over the Risca whitewash and put his side ahead by three.
Hale would bring the two sides level going into half-time with a penalty from 40 meters out sailing through the posts to close out the half.
Gleadall crossed just 12 minutes into the second half to give his side the lead after running in a lovely set-piece try.
The battle of the flyhalfs would take another turn when Hale grabbed a try of his own to once again take the scores level at 20 points a piece.
This incredible game took another turn when just two minutes later Blackwood broke the deadlock when Davies charged down a kick inside Risca's twenty-two.
The ball bounced up perfectly for the hooker to bumble his way over the try line.
Blackwood moved another try ahead when Kian Godwin linked up with Jacob Kenniford off the back of a great break by the winger.
Blackwood sealed the deal when Godwin topped off a great running try from the Blackwood pack.
Lloyd Thomas made the initial break towards the half-way before finding Godwin who should the Risca defence his speed to cross over and secure Blackwood's seventh straight league win.
Written by Max Drinkwater-James
There doesn't appear to be any tagged photos.
Please wait as the server processes your request. Do not attempt to refresh the page.
Processing
Processing