In performance terms Glasgow Warriors may have justified some of the claims made about the strides they have made under head coach Dave Rennie, but the outcome was all too familiar as they opened their Heineken Champions Cup account with defeat to English opposition at Scotstoun yesterday.

That need not, in itself, have been too damaging in a pool their opponents, Saracens, are expected to dominate since the perennial Pro14 play-off contenders should have every chance of taking sufficient points from their meetings with Cardiff Blues, back in this competition after a five year absence and tournament newcomers Lyon, to accompany the English champions into the knockout stages.

However, the naïve way in which they failed to claim so much as a bonus point from what was a fractious, fiercely contested encounter could yet cost them dearly and, in particular, they were left with reason to rue a late decision to kick to touch rather than take three points from a kickable penalty, which could have earned them a losing bonus point and changed the dynamics of the closing quarter during which the visitors were able to wind down the clock with the security of a two-score lead.

Knowing that they had to seize pretty much every opportunity that came their way, they also wasted the chance to take an early advantage when youngster Adam Hastings pushed a very straightforward penalty opportunity wide of the uprights. Making his first appearance for Glasgow in this competition since replacing the departed Finn Russell he had a difficult first quarter as Saracens applied a level of pressure he has not previously experienced and he was also unlucky that the touch-judge crucially failed to notice that he had forced Saracens centre Alex Lozowski into touch during the build-up to the game’s opening score.

That move was to prove the only try of the match, flanker Michael Rhodes ultimately claiming the touchdown, England play-maker Owen Farrell adding the conversion from wide on the left, then sending over a penalty soon afterwards to generate the gap would remain the difference between the teams at the end.

Farrell and Hastings were to exchange penalties later in the half to make it 13-3 at both the interval and at the end of the match following a scoreless second half.

What was perhaps the most crucial period of play came in the dying moments of the first, however, playing going close to five minutes into injury time as Glasgow repeatedly opted to kick to touch when awarded penalties as they pounded at the Saracens defence on their goal-line. England lock George Kruis eventually saved the situation for his side when he stole the ball at a ruck and while Glasgow immediately regained the ball and sent DTH van der Merwe over the line, they had done so illegally.

The mocking way in which another of the visitors’ England international forwards, Maro Itoji, joined in the Glasgow celebrations after the flanker, who was subsequently to receive the man-of-the-match award, realised before the home players had, that the decision had gone against them, was less than savoury, but it did speak to the edgy nature of proceedings and in turn represented something of an unintended compliment.

If they had not been quite as effective in turning pressure into points as they should have been, that Glasgow had kept taking it to such an imposing pack and came as close as they did, was an indicator of their improving confidence in their capacity to attack from the lineout and after the break they were then to demonstrate how they have come on defensively in that department, their co-captain Callum Gibbins the man who claimed a turnover as they held out when put under severe pressure at close range.

From that point there was a sense that a score either way and a try in particular, could have crucially changed the momentum of the game, either allowing Saracens the breathing space that might have given them the chance to go after a four try bonus point and a maximum haul in the closing stages, or putting them under the pressure of knowing that Glasgow were within a score of turning the match around. That neither side could conjure it only added to the tension, the match punctuated by several ill-tempered exchanges.

Having stayed in contention as long as they had, the home team might have provided the latest evidence that Pro14 teams boast an advantage through the sustained pace of play in that competition as compared with the more power-oriented English and French competitions had they been able to show a little more composure in the closing stages.

Instead both replacement George Turner and Hastings, who had otherwise recovered well from that difficult start to the match, were guilty of throwing speculative passes instead of showing the required patience to trust in their support when breaks had been made and holes created in the defence.

That, allied to that rash decision to go to touch late on when even those three points might just have forced Saracens to go about the closing stages in a different way, albeit they were never likely to do anything other than seek to close things down.

With Mark McCall, the Saracens director or rugby, looking a relieved man as he acknowledged that his side had been in a real fight, they have clearly won rather more respect than when thrashed by the English side in a Champions Cup quarter-final last year, but even a losing bonus point would have been a great deal more valuable.