Glasgow Warriors head coach Gregor Townsend praised his side’s commitment as they made it five RaboDirect PRO12 wins out of five against Scarlets.
In spite of having won their first four clashes of the season, Glasgow arrived in Wales knowing just how difficult the task ahead was having lost both home and away to the Scarlets last season.
But they got off to the perfect start as Ryan Grant went over for a try after just four minutes before Tim Swinson had Glasgow 14-6 ahead at half-time with a score of his own on the half hour.
And while Glasgow could only add a Duncan Weir penalty after the restart the Scarlets notched only two three-pointers themselves as the Warriors moved back to the summit with a 17-12 victory - much to the delight of Townsend.
“We are absolutely delighted with that result,” said Townsend.
“Scarlets are a really tough team, especially on their own patch so to get a result is huge.
“It was all down to the level of determination and effort. The guys had to dig deep and they did just that.”
Scarlets, who earned a losing bonus point, scored four penalty goals, three for fly-half Rhys Priestland and one from wing Jordan Williams.
Glasgow held on to win despite second half yellow cards for Sean Lamont and wing Niko Matawalu.
Lions centre Jonathan Davies captained the Scarlets for a second time, while Glasgow made 10 changes from the side that beat Zebre last week, including a first start of the campaign for Matawalu on the right wing.
Glasgow showed the confidence they have gained this season by scoring their first try after only two minutes.
They ignored the chance to kick a penalty in front of the posts with speedy Matawalu taking a tapped penalty resulting in Grant squeezing over for the try, converted by Weir.
The inconsistent Scarlets continued to be on their guard to stop the elusive running of Matawalu.
But they settled into the game when they got on the scoreboard with a Priestland penalty on 17 minutes.
The Scarlets also began getting the upper hand in the scrum but still had no answer to Glasgow’s running game which saw lock Swinson muscling his way over for the second try 10 minutes before half-time.
More dominance at the scrum earned the Scarlets a second Priestland penalty as they closed the gap to 14-6 just before the interval.
And the Scarlets dominated the opening exchanges of the second half, earning a penalty within a minute of the restart which Priestland converted to cut the deficit to only five points - but the league’s only unbeaten side were to prevail in the end.