The period just before half-time when they were reduced to 13 men was crucial as a couple of debatable sin-binnings, one after the other, ultimately decided the game.
The Scarlets got the try with the last move of the half through scrum-half Gareth Davies, although, once again, there was some debate in the Glasgow ranks about whether there was a double movement. But the match was not live on TV and there was no review.
It was certainly an encouraging performance which said a lot about Glasgow’s developing strength in depth, based on a stout defence and determination not to give the star-studded Llanelli backs any space in which to develop any momentum.
If the two team line-ups suggested an easy home win, the early action suggested anything but as Glasgow took the lead with the opening try of the match. Prop Moray Low got it from short range after his fellow forwards had stolen a lineout on the Scarlets line, but it was reward for a bright start by the visitors.
Rhys Priestland kicked a penalty for the Scarlets, following a ruck offence, but Ruaridh Jackson soon had a chance to extend Glasgow’s lead after he was high tackled in front of the posts.The stand-off landed the kick but injured his hamstring in the process and limped off – missing out on a much-needed opportunity to stake a claim to a Heineken Cup place and a chance to keep his Scotland jersey.
The bad news kept coming. First No.8 Ryan Wilson was adjudged to have been offside when he snapped up an interception that could well have brought a Glasgow try – instead it was a third Priestland penalty.
Then try scorer Low limped off with a knee injury after leading a counter-rucking drive and the weakened Glasgow line-up were missing a couple of their internationals.
Amazingly, though, it got worse. First flanker Rob Harley was sin-binned for a swinging arm then, as the Scarlets attacked from the resulting penalty, Wilson was adjudged to have killed the ball under the posts and was sent to join Harley on the sidelines.
Unsurprisingly, up against 13 men and a six-man pack, the Scarlets chose a series of scrums from a stream of penalties for offside – though the referee did seem to be influenced by the noisy home crowd on occasion. The Glasgow defence held out heroically, but it was too good to last and the Scarlets finally got over the line with the last move of the half. Ironically it came from an uncontested scrum, sub Ed Kalman himself being replaced by non-specialist tighthead Gordon Reid, which seemed to provide a better platform for the Scarlets and scrum-half Gareth Davies went over.
It was harsh on Glasgow to be trailing 16-8 at half-time following a first period which was far closer until the last few minutes of mayhem.
They scored six unanswered points in the second half through replacement stand-off Scott Wight, which turned into something of a war of attrition. Both sides had their chances as Wales wing George North got within a foot of going over in the left hand corner for the Scarlets, only for some desperate defence to get across to make the tackle.
Glasgow’s best chance came when right wing Tommy Seymour was put into space. He kicked ahead and re-gathered the ball but passed inside only after he had put a foot in touch. Fellow wing David Lemi collected the pass and touched down, so it was only a split second that denied them the score.
However, come the end of the game, both sides had their periods of pressure but the Scarlets were unable to get the try they wanted to deny Glasgow the bonus point, and Glasgow could not get the score of any kind to give them the win.
In the end, the visitors were obviously happy enough to leave with a losing bonus point that keeps them ahead of the Scarlets in the Rabo Direct. Given a penalty on their own 22 they were happy to kick the ball out to end the game rather than risking death or glory.
It said a lot for the strength in depth of Glasgow these days that they could make so many changes and earn a losing bonus point at a place where full strength teams have left empty handed. Plenty of encouragement, but frustration as well.
Scorers: Scarlets: Try: G Davies. Con: Priestland. Pens: Priestland 3. Glasgow: Try: Low. Pens: Wight 2, Jackson.
Scarlets: Newton, North, S Williams, J Davies, Lamont, Priestland, G Davies, I Thomas, Rees, Manu, Reed, Day, McCusker, Edwards, Morgan. Subs: Owens, R Jones, R Thomas, Turnbull, Shingler, R Williams, S Jones, Iongi.
Glasgow: Murchie, Seymour, Dewey, Morrison (c), Lemi, Jackson, Pyrgos, Welsh, Thomson, Low, Verbakel, Ryder, Harley, Fusaro, Wilson. Subs: Gillies, Reid, Kalman, Forrester, Beattie, McConnell, Dunbar, Wight.
Referee: D Phillips (Ire). Attendance: 9,869.
• Aironi claimed back-to-back home wins in the RaboDirect Pro12 with a 20-6 victory over Connacht in a bottom-of-the-table clash. Stand-off Luciano Orquera kicked a 15-point haul and Sinoti Sinoti scored a try. Leinster extended their lead at the top with a 23-19 win at Cardiff.