Llanelli staged a brilliant recovery to snatch the Konica Minolta Cup from Pontypridd at the Millennium Stadium.
Three tries from Neil Boobyer, Bryn Griffiths and Chris MacDonald in the last 10 minutes saw Llanelli come from 8-24 down to win it at the death.
Llanelli fly-half Thomas Marks had struggled with the boot but kicked the crucial conversion needed for victory.
It was desperately hard on Ponty who had controlled much of the second half, with fly-half Dai Flanagan outstanding.
Flanagan kicked two penalties in a tight first half, but Llanelli led 8-6 at the break thanks to a Marks penalty and then an opportunist try in first-half injury time.
Pontypridd failed to control a lineout near their own line, allowing Llanelli prop David Maddocks to pounce on the bobbling ball over the try line.
But Flanagan soon put Pontypridd back in the lead after the restart with his third penalty of the afternoon.
The Valleys side then stretched away when Richard Fussell broke brilliantly through the Llanelli midfield before chipping ahead, gathering and feeding Dafydd Lockyer for a try.
Man-of-the-match Flanagan missed the conversion but soon made amends with another penalty.
It seemed Pontypridd had the trophy all sown up on 67 minutes when wing Darren Berry raced away for a converted try that put the black and whites 24-8 ahead.
But then came Llanelli's incredible recovery as Boobyer muscled his way over, Griffiths scampered down the wing following Danny Hodges' backdoor pass, then MacDonald picked up from a ruck and went over from close range.
Flanagan had one last chance to wrest it back for Pontypridd deep into injury time, put the penalty chance was on the left touchline at the very extreme of his range and fell agonisingly wide.
Llanelli: L Byrne; Rogers, Daniels, Lewis, Gravell; Marks, MacDonald; Maddocks, Hawkins, K Jones., Rowe, Griffiths, T Bowen, M Evans, Cunningham.
Replacements: Ohlsson, Hughes, Roberts, C Thomas, R Williams, Boobyer, Rimmer.
Pontypridd: Morgan Stoddart; Darren Berry, Tom Riley, Dafydd Lockyer, Richard Fussell; Dai Flanagan, Gareth Jones; Stuart Williams, Duane Goodfield, Ryan Harford, Chris Martenko, Grant Harrington, Wayne O'Connor, Rhys Shellard, Dan Godfrey (capt).
Replacements: Paul John/Pocock, Jason Pocock, Jason Lewis, Ben Phillips, Gerald Cox, Lee Evans, Danny Hodge.
Referee: Nigel Williams (Wales).