Llanelli denied Pontypridd a league and cup double with a well-earned victory in the Welsh Premiership play-off final at Sardis Road.
Dan Newton and Nic Reynolds crossed for first-half tries for Llanelli, before Lee Williams' score put the visitors in control 24-6 up with 20 minutes left.
Pontypridd fought back bravely with tries from Huw Dowden and Rhys Downes.
But Llanelli held on in a frantic final five minutes to lift the Premiership crown for the first time.
The Parc y Scarlets outfit had finished 16 points behind top-of-the-table Ponty after the end of the regular season, but they proved themselves to be worthy winners on the night.
Their task was made significantly easier, though, when Ponty flanker Wayne O'Connor was sent off in the first half for using his knee in a ruck.
Pontypridd: A. Thomas; Wyatt, Lockyer, G. Dacey, O. Williams; Humberstone, Jones; S. Williams, K. Dacey, Harford, Locke, Savage, Waters, O'Connor, Dicomidis.
Replacements: Downes, Gunter, L. Williams, Dowden, Siggery, Hill, Hobbs.
Llanelli: Newton; Ford, Reynolds, J. Lewis, L. Williams; S. Shingler, G. Davies; John, Hawkins, S. Gardiner, A. Powell, Day, Eager, Gilbert, Cudd.
Replacements: S. Hopkins, Lawrence, R. Jones, White, A. Powell, J. James, Keenan.
Referee: David Jones (Wales).