The victory for Dale McIntosh's men will also make up for their shock SWALEC Cup final defeat to Cross Keys although he would have to concede his side made life difficult for themselves.
Ponty had the better of the first half but let Llanelli back in with some poor kicking and decision making. The home side also finished the match with only 14 men after replacement Gary Williams received a straight red card from referee Ian Davies for dangerously upending Llanelli full back Dan Newton in the 76th minute.
In the first half clean line breaks were at a premium with Pontypridd midfielder Dafydd Lockyer slicing through the Llanelli defence on a rare decisive foray in the greasy conditions.
Ponty skipper Chris Dicomidis was also prominent with a couple of charging runs but the home side's inability to retain the ball in the tackle ensured momentum wasn't maintained in promising situations.
Aimless kicking as the first half progressed didn't aid Ponty's cause as Llanelli clawed their way back into the game with two successful penalties by winger Jordan Williams.
Llanelli flanker Nic Cudd was given a yellow card in the 13th minute and during his stay in the sin bin Ponty edged out to a 9-0 lead through Williams' boot.
Jordan Williams hit back with his first success with the boot in the 33rd minute. He had a chance to further reduce the arrears but his long range shot hit an upright.
Ponty's set-piece, which held the upper hand throughout, destroyed a Llanelli scrum early in the second spell to give Lewis Williams his fourth success of the night to give his side a 12-3 lead.
Llanelli hit back with a well worked try when Craig Price stormed over in the corner after Jordan Williams sent him clear with the try scoring pass. Williams then converted an excellent conversion from wide out to bring the score to 12-10.
Lewis Williams edged his side further in front with his fifth penalty with his namesake replying to set up a nail biting finish for the Ponty fans but the heartache from last year's defeat was quickly forgotten when referee Ian Davies signalled full time to send the players and fans into ecstasy.