Ulster moved level on points with Guinness PRO12 leaders Glasgow after they saw off the Scarlets 25-20 at Kingspan Stadium on Friday.
Tries from Irish internationals Craig Gilroy and Luke Marshall, and complemented by a further touch down from the ever-reliable Ruan Pienaar enabled Ulster to secure the win at Ravenhill.
The South African added two penalties and conversions to see his side home in a keenly contested, but flawed game.
The Scarlets raced ahead in the first-half with an opportunistic try from John Barclay, but failed to capitalise in the second period. Indeed the 20 minutes after half-time became the Ulster show as the home side emphatically seized the advantage with a display of ruthless, running rugby.
The Irishmen are on a roll at the moment, and this welcome win leaves their play-off ambitions looking much more secure. The Welsh visitors did well, though, to fight back with a losing bonus point courtesy of Kristian Phillips’ late try, and the Irishmen may lament their failure to obtain maximum points here.
The game started untidily, with the opening few minutes characterised by wayward kicking. Ulster had the best chance to open the scoring after three minutes when Darren Cave made a trademark swerving break, but the Irish centre fluffed his pass with the hard work having already been done.
The Scarlets rallied thereafter, and built some territory of their own, allowing Steve Shingler a penalty attempt on eleven minutes, but his effort fell wide. But the fly-half was gifted another chance just a minute later, and he landed the more difficult kick to earn the Scarlets a 0-3 lead.
No sooner had that gone over, then Pienaar had a chance to equalise, but sadly for Ulster his effort drifted beyond the posts. The game was delicately poised at this stage, with no side gaining the clear upper hand. Shingler, though, had a fantastic chance to extend the Scarlets' lead on 20 minutes, but scuffed the simple kick. By the end of the first quarter, then, neither team had achieved any real dominance.
The hosts, for their part, were struggling to gain momentum, but Pienaar levelled the score on 24 minutes with a sweetly struck kick. But parity proved short-lived as Shingler re-established the lead for his side on 28 minutes with another penalty.
The lead didn't last long, however, and Ulster's South African talisman restored equilibrium on 32 minutes to make it 6-6.
But calamity ensued for the hosts barely five minutes later. Ulster dubiously attempted to run the ball out of their own 22 and Ian Humphreys pass failed to find its target, enabling a grateful Barclay to sweep up the stray ball and saunter unopposed to score. Shingler converted the number eight's effort to establish a 6-13 lead for the Scarlets. By half-time, the game was still in the balance with the Scarlets certainly having the obvious advantage.
But it was the Irishmen that made the brighter start to the second-half, and it couldn't have commenced better for the hosts as Gilroy danced through several Scarlets defenders before touching down in the corner. Pienaar missed the awkward conversion, though, to leave the score 11-13.
But a rejuvenated Ulster duly scored next, as Humphreys took the ball in the 22; before unloading a neat scissors inside to Marshall to score Ulster's second try of the contest. Piennar converted this time to propel his side into an 18-11 lead.
Ulster looked like a team possessed post-interval, as the hosts flung the ball about with a concerted ambition. And the floodgates consequently opened. Thus on 59 minutes Pienaar went over from close range, and inevitably converted his own try to make it a healthy 25-13 to the Belfast men.
The Scarlets enjoyed a mini-renaissance in the final phase of the match, as a frustrated Ulster repeatedly coughed up possession. The Welshmen went through the phases in the Ulster half, but despite their admirable industry, they couldn't negotiate a way through the well-drilled home defence.
The hosts' pursuit of the bonus-point thus became rather desparate, and in truth they rarely looked like troubling the Scarlets' rearguard throughout the last 20 minutes.
In the end, it was the Scarlets who had the last say in this contest as Phillips evaded the hitherto impregnable Ulster defence to bag his consolation score and with it the losing bonus-point. Shingler converted to bring his team within a score, but it was the final act. A vital win for Ulster then, but the Irishmen will assuredly rue their failure to acquire that elusive bonus point.
Tries: Gilroy, L Marshall, Pienaar
Con: Pienaar 2
Pen: Pienaar 2
Tries: Barclay, Phillips
Con: Shingler 2
Pen: Shingler 2
Ulster: 15 Louis Ludik, 14 Craig Gilroy, 13 Darren Cave, 12 Luke Marshall, 11 Michael Allen, 10 Ian Humphreys, 9 Ruan Pienaar, 8 Nick Williams, 7 Clive Ross, 6 Roger Wilson (c), 5 Franco Van der Merwe, 4 Dan Tuohy, 3 Wiahahn Herbst, 2 Rob Herring, 1 Callum Black.
Replacements: 16 John Andrew, 17 Andrew Warwick, 18 Bronson Ross, 19 Lewis Stevenson, 20 Mike McComish, 21 Paul Marshall, 22 Mike Stanley, 23 Rory Scholes.
Scarlets: 15 Jordan Williams, 14 Harry Robinson, 13 Regan King, 12 Hadleigh Parkes, 11 Michael Tagicakibau, 10 Steven Shingler, 9 Aled Davies, 8 John Barclay, 7 James Davies, 6 Aaron Shingler, 5 Lewis Rawlins, 4 George Earle, 3 Peter Edwards, 2 Ken Owens (c), 1 Phil John.
Replacements: 16 Ryan Elias, 17 Rhys Thomas, 18 Jacobie Adriaanse, 19 Jack Payne, 20 Rob McCusker, 21 Gareth Davies, 22 Adam Warren, 23 Kristian Phillips.
Referee: Ben Whitehouse (Wales)
Assistant referees: Barry Kieran (Ireland), Dermot Blake (Ireland)
Television match official: Marshall Kilgore (Ireland)
Assessor: Bertie Smith (Ireland)
By Rory McGimpsey