Ian Humphreys touched down twice as Ulster battled past Scarlets to move second in the Magners League table with a 20-18 victory at Ravenhill.
For Ulster, it was a sixth successive Magners League victory which leaves them well-placed to snatch an end-of-season play-off spot.
The Scarlets responded through a superb Jonathan Davies score and an Aaron Shingler intercept try, but the result leaves their top-four ambitions in tatters.
However, Ulster started the slower and for the first 20 minutes, it was the Scarlets who dominated play and duly opened the scoring through a penalty from stand-off Stephen Jones.
Winger Morgan Stoddart made two blistering breaks but the Welsh team couldn't take advantage. And they were made to pay when Humphreys dummied his way to the line, Ruan Pienaar converting.
The hosts almost went over again not long after, but a superb covering tackle from number eight Ben Morgan denied winger Andrew Trimble.
Jones and Pienaar then traded penalties before the South African scrum-half kicked an incredible 50-yard three pointer from out wide, to leave the match finely balanced at 13-6 at half-time.
Within the first minute of the second period, centre Davies shocked the Ravenhill crowd when he ran 40 metres unopposed to touch down.
Flanker Josh Turnbull was then harshly sin-binned for the away team but they managed to last the period without conceding a point.
However, Ulster secured the win through a converted Humphreys try even though back-row Shingler gave his side hope with just three minutes remaining, Rhys Priestland adding the extras.
Tries: Humphreys 2
Cons: Pienaar 2
Pens: Pienaar 2
Tries: Davies, Shingler
Pens: SM Jones 2
Ulster: 15 Adam D'Arcy, 14 Andrew Trimble, 13 Nevin Spence, 12 Paddy Wallace, 11 Simon Danielli, 10 Ian Humphreys, 9 Ruan Pienaar; 8 Pedrie Wannenburg 7 Willie Faloon, 6 Robbie Diack, 5 Dab Tuohy, 4 Johan Muller, 3 BJ Botha, 2 Rory Best (c), 1 Tom Court.
Replacements:16 Andi Kyriacou, 17 Paddy McAllister, 18 Declan Fitzpatrick, 19 Tim Barker, 20 Chris Henry, 21 Paul Marshall, 22 Ian Whitten, 23 Craig Gilroy.
Scarlets: 15 Rhys Priestland, 14 Gareth Maule, 13 Regan King, 12 Jon Davies, 11 Morgan Stoddart, 10 Stephen Jones, 9 Tavis Knoyle, 8 Ben Morgan. 7 Johnathan Edwards, 6 Josh Turnbull, 5 Rob McCusker, 4 Lou Reed, 3 Rhys Thomas, 2 Matthew Rees (capt), 1 Iestyn Thomas.
Replacements: 16 Emyr Phillips, 17 Rhodri Jones, 18 Peter Edwards, 19 Aaron Shingler, 20 David Lyons, 21 Martin Roberts, 22 Daniel Evans, 23 Scott Williams.
Referee: Graham Knox (SRU)