A good crowd turned up to watch a fierce contest, yet it never once spilled over and there was hardly any daylight between two fit and powerful teams.
Credit also must go to the popular Abertillery referee Sean Brickell, who has emerged this season as a top-class Premiership official and who allowed the game to flow without overusing the whistle.
Merthyr had a splendid half-back pair of Neil Burnett and Ryan Harries, while the ball-handling skills of loose-head prop James Howe showed how he notched 12 tries in the league this season and Matthew Rees was a lively flanker.
Gilfach gave a fine account of themselves with Pontypridd hooker Huw Dowden always a threat and powerful Ricky Priday leading the pack well. Ian Davies kept up a stream of passes from good ball from his pack and captain and wing Nathan Walters was always troublesome.
It was Gilfach who opened stronger and a forward drive saw tight-head prop Mike Hughes gain a fifth-minute try, but the strong left boot of Burnett cut the lead with a penalty soon afterwards.
In the 24th minute Merthyr hooker Jonathan Watkins used great strength to take three tacklers over in the corner and it was 8-5 to half-time, though their 32-years-old full back Craig Morgan, capped ten times for Wales, just failed to score after a long kick and chase.
Two minutes after the restart Ian Davies put over a penalty for Gilfach, but Burnett hit a magnificent long low shot over three minutes later as Merthyr regained a lead they were not to lose.
Then came a decisive break by centre Matthew John and wing James Woods raced over in the corner, though Gilfach centres Shaun Roberts and Adrian Williams went within inches of pulling a try back.
Gilfach kept coming and the Merthyr defence was nothing short of brilliant, but after 65 minutes Davies and Williams sent replacement flanker Lee Purnell diving in and Davies converted.
Just one minute later Merthyr caught Gilfach cold and the lively Howe gathered a high kick to score too far out for Burnett to convert.
Davies had a long penalty effort that just missed, but both sides hammered away without a further score coming, while Merthyr knew that a draw would see them winners by way of a 3-2 try-count.
The remaining 11 minutes brought no further score and Merthyr No 8 Gareth Williams was presented with the cup by Martin Anderson, Regional Director of Molson Coors.
Scorers:
Merthyr – Tries: J Watkins, J Woods, J Howe. Pens: N Burnett 2.
Gilfach Goch – Tries: M Hughes, L Purnell. Con: I Davies. Pen: I Davies