Welsh international winger Matthew Watkins helped himself to a first half try - one which made him the league's record try scorer - while flanker Jonathan Edwards and prop Deacon Manu also crossed the Ulster whitewash in the opening 40 minutes.

Replacement winger Mark Jones scooted in under the posts for the hosts' bonus point try, twelve minutes after the break, and the damage was well and truly done.

Ulster's early season slump continued with Tommy Bowe's 33rd-minute breakaway score proving one of the only highlights for the province. Ulster had never won in six previous visits to Stradey Park and despite the return of five members of the Ireland World Cup squad, Mark McCall's men struggled throughout this one-sided encounter.

They did get off the mark first with returning fly-half Paddy Wallace making up for an earlier miss by landing a 14th-minute penalty kick from the right.

But it was all about Llanelli and their free-running style and they gave Ulster a glimpse of what was to come when full-back Morgan Stoddart made a line-break just two minutes later.

Stoddart's progress was halted by a thundering shoulder charge by Stephen Ferris and after the Ulster number eight got a talking to from referee Malcolm Changleng, impressive young fly-half Rhys Priestland put the penalty through the uprights.

The Scarlets went 10-3 ahead when late call-up Nathan Brew charged through a gap on the right, ruck ball was secured and swung back out to the left for Priestland to put Watkins haring through and over for his league record 29th try.

The Ulster defence had been hopelessly exposed and although they were finding some joy at lineout time, the visitors lacked any continuity despite the best efforts of stand-in captain Isaac Boss.

The Scarlets missed out on a second try when flanker Edwards brilliantly shrugged off three tacklers just outside his 22 and set off on a pacy attack which ended with a Priestland kick to the right corner needing to be touched down by Ulster full-back Bryn Cunningham.

Ulster struck back just after the half-hour when a poor lineout throw from home hooker Ken Owens sailed over the top and into midfield when Seamus Mallon took control of it. He galloped forward and gave a scissors pass to his centre partner Bowe who had the pace to dash over for the try from 60 metres out.

Wallace pushed his conversion attempt to the right and wide and despite that try, things went from bad to worse for McCall's side in the lead-up to half-time.

The defence was breached four minutes before the break and some quick offloading led to Owens sending a looping pass out to the left for the unchallenged Edwards to ghost over for his third try in two games.

A harsh sin-binning followed for Ulster flanker Neil McMillan as he was punished for repeated infringements at the breakdown.

Down to 14 men and with their defence all at sea, Ulster leaked another try when Manu was allowed to charge over unchallenged off the back of an injury-time maul, with Priestland's conversion handing the Scarlets a 22-8 interval lead.

With their fourth win in five league games in sight, the Scarlets secured the bonus point when pressure near the Ulster line told and Jones cut past a weak tackle from Bryan Young to sail over under the posts.

Priestland, whose assured kicking helped him win the man of the match award, added the extras and Ulster were 21 points in arrears.

Games as they were, Ulster never got within sight of the hosts' whitewash and a 71st-minute penalty from Priestland proved to be the final scoring act as the Scarlets kept up their record of not losing a league match at home to a non-Welsh side since September 2005.