Scarlets 34-10 Ulster
Tadhg Beirne wrestled the ball from back-row rival Nick Timoney behind the Ulster line to bag a brilliant bonus-point try for the Scarlets to keep them well in the hunt for a Guinness PRO14 play-off place.
Ulster arrived at Parc y Scarlets knowing nothing less than a win was going to be good enough to put pressure on the top three and they got off to a flying start when a Tommy Bowe break led to a try for centre Stuart McCloskey within two minutes.
The visitors looked the stronger side for long periods of the opening half and had a second try for Timoney ruled out by the TMO for interference on home scrum half Jonathan Evans at an earlier breakdown.
That was a turning point in the game.
It meant the Scarlets changed ends trailing only 7-3 after Dan Jones kicked a penalty.
They dominated the second period and picked up their bonus-point four minutes from time to close the gap on Conference B leaders Leinster to a mere three points.
The two teams meet at Parc Y Scarlets on 3 March in Round 17, while Ulster have to go away and lick their wounds as they try to find a way to close a five point gap on third placed Edinburgh.
Four minutes after the re-start the home side converted a long period of pressure when Ioan Nicholas dived over in the left corner. Jones added a superb touchline conversion to edge his side ahead 10-7.
James Davies was then penalised for staying on the ball too long at the breakdown on his 22 and that gave John Cooney the chance to level things up. Jones kicked a simple penalty five minutes later after full back Tom Williams had been denied a try in a race with McCloskey.
Wales Under 20 wing Ryan Conbeer didn't take long to make an impact as he beat three defenders in a brilliant 60 metre run to the posts for a wonder try six minutes after coming onto the field.
Jones improved the try to take a 10 point lead and then the outside half cleverly chipped over the top of the Ulster defence to enable his centre Paul Asquith to race onto it and bag another try.
Jones duly converted and there was no denying the Scarlets their bonus-point as Beirne ripped the ball free and claimed the try. Jones stepped up to kick the conversion and take his tally for the night to 14 points.