Rovers conceded 5 goals for the second home game running and look destined for relegation on current form.
Visitors Dereham Town started brightly, with Joe Gatting and Daniel Beaumont firing wide. The deadlock was broken in the 19th minute, Dion Frary smashing the ball past Rovers stopper Tyler McCarthy.
The talking point of the first half was visiting Ryman League Chairman donning his boots as he replaced injured linesman Mario Stetakovic.
With the second half barely five minutes old, Beaumont tapped in from close range to double Dereham's lead. The visitors third came from a swift counter following a Rovers corner, with Gatting running into the box to fire past McCarthy.
Dereham's fourth came just after the hour and in comical fashion, with McCarthy firing a quick goalkick against Nikki Beale only to see it rebound into the goal. A despondent Rovers conceded their fifth with ten minutes remaining, Rhys Logan at the back post to head home from close range.