Ulster paid the price for some sloppy defending in the opening quarter and never really recovered as they lost their opening Magners League match.
The Scarlets had taken a 10-0 lead after 20 minutes, Welsh international outhalf Stephen Jones slotting over a penalty and then adding the extras to Darren Daniel's try, after Andrew Trimble let the winger in for a 'soft' score.
Ulster did fight their way back into the game well, but failed to make use of the wind advantage and their possession.
Fullback, Clinton Schifcofske kicked three penalties from six attempts to leave Ulster trailing 10-9 at the break.
In the first five minutes of the second half, Jones extended the lead for Scarlets to 13-9, unfortunate to see a third penalty rebound off the left pole.
Conditions deteriorated, with the wind increasing in the second half which aided the Scarlets who were seeking their first Magners League win against the Irish Province in Belfast.
That victory drew ever nearer when Jones banged over another penalty on 58 minutes, with Ulster not looking like creating anything and not able to get out of their own half during the entire second period.
The defence did hold firm at the end though as Scarlets pressed to seal the deserved victory, although Ulster finally got into opposition half and came so close to snatching at least a share of the spoils.
ULSTER: C Schifcofske; A Trimble, D Cave, R Dewey, T Nagusa; P Wallace, I Boss; J Fitzpatrick, R Best (capt), B Botha, C Del Fava, E O'Donoghue, M McCullough, K Dawson, R Diack.


Replacements: N Brady, T Court (Botha 65), R Caldwell ( Del Fava 26), D Pollock (Dawson 65), C Willis (Boss 65), N O'Connor (Cave 76), B Cunningham.

Scorers:
Pens: Schifcofske (3)
SCARLETS: M Stoddard; D Daniel, R Higgitt, G Evans, M Jones; S Jones, S Martens; I Thomas, M Rees, K Meeuws, L Reed, S Maling, S Easterby (c), G Thomas, D Lyons.

Replacements: D Manu (Meeuws 65), K Owens (Rees 76), V Cooper (Maling 65), D Jones (G Thomas 65), M Roberts (Martens 71) C Thomas, N Brew.

Scorers:
Tries: Daniel
Pens: Jones (3)
Con: Jones
Ref: Peter Allen (Scotland)
Att: 7368