Glasgow maintained their 100% RaboDirect PRO12 record and their place at the top of the table with a victory that was more gritty than spectacular, but which showed again that they are serious title contenders.
Not many sides come to Parc y Scarlets and play with the control and assurance that Gregor Townsend's side summoned last night. They had no favours whatsoever, and fewer still from the two Welsh touch judges, but they dug deep and lost neither their determination nor their shape to close out the game.
Townsend wore an expression of relief at the finish, but he could be hugely satisfied as well. He said: "We started with good intentions, defended well and stuck in to the end. A few of those players haven't had much rugby this season, so I'm really pleased for them."
Townsend could be especially happy with the contribution of Duncan Weir following the fly-half's six-month absence through injury. Niko Matawalu, playing on the wing, also showed the sharpness he brings at scrum-half, while the Indian summer of Sean Lamont was lengthened by another powerful display.
There was also a wonderful collective effort by the pack, They struggled at times in the scrums - although some of their struggles seemed to be with the referee's interpretations - but in the ruck they cleared out defenders with menace and power. Chris Fusaro, up against former Glasgow flanker John Barclay, was also outstanding, with some memorable tackles and turnovers.
After their hefty defeat here last season, Glasgow had all but billed the game as a revenge mission, and they exacted swift punishment when they put a try on the board after just three minutes. It was sweeter still that the only Scarlets hand that had touched the ball by that point was the one that knocked on the Glasgow kick-off, although that detail probably eluded Ryan Grant as he toppled over for the score.
The Scarlets looked shell-shocked by Glasgow's start, but the effect was temporary as they soon built momentum of their own through the phases. Yet on a night when the bars of Parc y Scarlets were offering to knock 2p off the price of a pint for every home point scored, Glasgow seemed to be in league with the catering department by putting up a miserly defensive display. In truth, the Scarlets did not sniff the Glasgow try line in the first half, their six points in that period being gathered only with a brace of penalties by Rhys Priestland. Neither was the prospect of cheap beer strengthened by the string of handling errors Scarlets made, with even Jonathan Davies guilty of a couple.
Instead, it was Glasgow who showed energy and imagination going forward. Those qualities were rewarded in the 30th minute when Mark Bennett made precious yards with a burst down the left, the ball was moved across the field and, after a series of rucks on the line, Tom Swinson twisted over for the second try. The score put Glasgow 14-6 ahead at the break, Weir having kicked the two calm conversions. In truth, the margin flattered Glasgow as a measure of territory controlled, but it was a decent reflection of their assurance under pressure and their measured approach in possession.
Scarlets hit back with another Priestland penalty after the break, but although the Welsh side had lifted their game they could still not take control of the match. A fourth penalty, by Jordan Williams, closed the gap to two points in the 58th minute, but Weir soon cancelled it out.
Along the way, Lamont and Matawalu spent time in the sin bin. Both calls were harsh, but it was another positive reflection for Glasgow that they could shrug off those inconveniences so well.
Scarlets: L Williams; N Reynolds, J Davies (capt), G Maule (A Warren, 77), J Williams; R Priestland, R Williams (A Davies, 74); P John (R Evans 58), K Owens, J Adriaanse (R Jones, 74), G Earle, J Snyman (J Ball, 52), J Turnbull (R Jones 68-72), J Barclay, R McCusker (A Shingler, 30).
Glasgow: S Maitland; N Matawalu, M Bennett (S Wight 77), A Dunbar, S Lamont; D Weir, C Cusiter (DTH Van der Merwe, 60); R Grant (J Yanuyanutawa, 67), P MacArthur (F Brown, 66), M Low (J Welsh, 48), T Swinson, A Kellock (captain), R Harley (J Eddie, 66), C Fusaro, R Vernon (A Ashe, 48).
Referee: G Vivarini (Italy)