The victory keeps them right in contention at the top of division one of the National League, currently lying in second place just two points behind leaders Pontypool.
The clash at Tredegar was never going to be an easy one for the Otters as they looked to get their promotion challenge back into gear, but they just about had the edge and thoroughly deserved their win.
Ironically, however, for a team who are noted for their pace and precision behind the scrum, it was prop forward Andy Howell who bagged the winning try with little more than 10 minutes remaining.
The touchdown came after an incisive attack involving centre Elgan Vittle and another front row forward Phil John, before a delighted Howell took the final pass to crash over the line.
Despite facing the wind in the first half, though, it was Tredegar who took the battle to Narberth early on. Indeed, they had the better of the opening exchanges as they built a useful 13-6 lead by the interval.
Their points came from right wing Daniel Morris, who crossed for a try, converted by Jeremy Lloyd, who also kicked a penalty, as did Paul Tatcher.
The Otters replied with an early penalty by outside-half Simon Daniels and another by fullback Gareth James.
James took over the kicking duties after moving up to the fly-half berth in place of Daniels who had to leave the field after quarter-of-an-hour with a hamstring injury.
Replacement Adrian Killa came on to take over the vacated fullback position.
After the turnaround, Narberth, now facing the wind, quickly got back on terms when another free-flowing move saw wing Daniel Gravell go haring down the touchline before linking with supporting second row Jamie Bohata who crossed for their opening try.
James added the extras with a successful conversion to tie the scores - and so it was game on!
After that, both sides battled tenaciously for the winning score, and happily for Narberth it was that man Howell who popped up to claim it, with James also landing the conversion for good measure.
Tomorrow (Saturday), Narberth entertain Aberavon at the Lewis Lloyd in what promises to be another exciting clash.
Narberth fielded: Gareth James, Daniel Gravell, Mike Jones, Elgan Vittle, Nick Jones, Simon Daniel (Adrian Killa), Ryan Williams (Chris MacDonald), Phil Jones, Craig Hawkins, Andrew Howell, Emori Katalau, Jamie Bohata (Jason Jennings), Simon Davies, Meurig Daniel (Matthew Evans), Akerei Malasala (Gareth Bennett).