The hosts started brightly with the energetic Karwell Chambers initiating several promising opportunities for the Foresters.
Kings safely weathered the early storm and were soon on the offensive themselves with debutants Ryan Hope and Josh Hutchinson both looking immediately effective.
However, Kings suffered an early setback when versatile midfielder Ryan Plowright was injured attempting to convert a Josh Chamberlain cross, a source which was to prove extremely fruitful for Kings as the afternoon progressed.
Dean Hitchcock replaced hospital bound Plowright and was soon combining well in midfield. Kings were gradually gaining the ascendancy and broke the deadlock in the 31st minute when Hutchinson bravely contested a Chamberlain cross to head home.
Kings had their tails up now and a second goal quickly followed when a penetrating Josh Chamberlain run ended with a miscued shot falling to fellow wing back Steve Ward who finished confidently with a low drive to leave the hosts a little unfortunate to be two down at the break.
Cinderford opened the second period in determined fashion but Kings’ rear-guard were in no mood to surrender their advantage. In fact, it was Kings who thought they had added to their lead on the hour when a superbly executed overhead kick by Hutchinson found the net only to be ruled out for offside.
It was to be a brief respite however as the points were effectively sealed just minutes later when Josh Chamberlain completed a hat trick of assists by crossing for Duku to chest down and prod home.
Kings were in dominant mood now and the dangerous Duku completed the scoring with a brilliant solo run which saw him power clear of the home defence to blast home.
The final deficit was tough on the Foresters, who never gave up but found King’s firepower just too much to cope with on the day.
Kings now have two home games in the Southern League Premier - at Hitchin Town on Tuesday, followed by Kettering Town on Saturday. They then visit Basingstoke Town on Tuesday, October 18.