Northampton may be struggling in the Zurich Premiership but have come alive in the Heineken Cup with a second victory that's sets up mouth-watering back-to-back clashes with French giants Toulouse.
Man-of-the-match Wylie Human did the damage with two tries, both created by outstanding kiwi full-back Bruce Reihana as Northampton followed up their win over Glasgow in style.
For the Scarlets, however, defeat a week after a home loss to Toulouse, means they are facing huge uphill battle to qualify and now need other results so to their way if they are to avoid crashing out at the Pool stage in only the second time in their history.
The game turned in the space of five minutes at the end of the first half just moments after Scarlets outside half Arwel Thomas missed the chance to equalise when he pulled his penalty just wide of the posts.
His wayward up and under from the restart gifted possession back to Northampton who back with a superb try. Mark Robinson sent Ben Cohen charging up through the middle of the field, and quick hands from the Saints backs saw flanker Darren Fox pick up and charge over from close range.
Moments later and Northampton delivered the killer blow when Thomas was robbed of possession in midfield. A swift movement saw Human dart over in the corner.
The Scarlets bought on young outside half Gareth Bowen but while they were competitive in the second half, the damage had already been done.
Six minutes from time the Saints wrapped up a comfortable victory when Reihana sent Human flying for his second try.