The second-placed Scarlets, who started with back rower Dafydd Jones partnering Lou Reed in the second row, were hoping to kick on from their recent win over Glasgow Warriors but a resilient Ulster team coped better with the conditions and showed the right amount of "heart and courage", according to coach Williams, to secure another encouraging result.

The Ulster management made five changes to the side that started the six-try success over the Dragons with Rory Best and Paddy Wallace, who were in action for Ireland against Scotland last weekend, two of the new inclusions.

The hosts were suitably fired up for the occasion after being presented with their jerseys and given a talk by former Ulster and Ireland lock Paddy Johns. However, the Ravenhill scoreboard remained untroubled until the 38th-minute.

The Scarlets had been largely frustrated up to that point as Ulster, despite facing into a strong wind, had the better of the early exchanges with their pack in very good form.

But the only scoring chance Ulster could create was a tenth-minute penalty, set up by a midfield break from Wallace. Young fly-half Niall O'Connor hit the post with the kick and it was his opposite number Rhys Priestland who opened the scoring some 28 minutes later.

He fired an easy penalty through the uprights after Ulster prop Tom Court was penalised for hands in the ruck. There was still time before the interval for Ulster to slip into the lead at 5-3.

With the Ulster pack again to the fore - Matt McCullough and Stephen Ferris worked their socks off all night - the home side made 20 metres with Court carrying on and then scrum half Isaac Boss took his chance to scramble over from close range.

O'Connor missed the conversion but, as the rain began to teem down, it was the perfect time for Ulster to score.
Scarlets boss Phil Davies shook up his side for the restart by bringing on experienced back rowers Alix Popham and Simon Easterby. Nonetheless, Ulster were 8-3 up within five minutes as O'Connor sent over a superb penalty from distance.

Priestland increased his influence in the 63rd-minute when he sped through a gap and left O'Connor for dead as he galloped over for an unconverted try.

Williams responded by bringing the hard-hitting Justin Fitzpatrick, Neil Best and Carlo Del Fava into the fray for the final quarter and willed on by a boisterous crowd, Ulster managed to push their forward dominance home.

Ulster charged up the other end and camped themselves within five metres of the visitors' whitewash. Four scrums collapsed in the intervening minutes but Ulster's patience was rewarded in the 72nd-minute when man-of-the-match McCullough barged his way over after a neat pass from Fitzpatrick.

With the league's top try scorer this season Regan King kept quiet during the second half, the Scarlets' attacking threats were on the wane.

Under pressure right to the finish, Davies' men missed out a losing bonus point when flanker Best cut past two defenders to power over, allowing O'Connor to convert and put the seal on Ulster's first league success over the Welsh region since September 2006.