Brute strength and intelligence.

Glasgow matched Montpellier's muscle in this ferocious, often fractious contest, but they were miles ahead of the French side in the mental game. They defended brilliantly, managed the scoreboard cleverly and landed killer blows around the hour mark after a third quarter spent largely on the back foot. Their European dream goes on.

In fact, Montpellier needed a penalty try, and a soft one at that, right at the death to put a flattering gloss on the scoreline and salvage a loser's bonus point. On balance, they probably deserved the latter, but it is likely to make little difference to their Champions Cup prospects. With Toulouse beating Bath at the Recreation Ground, pool 4 now looks like a two-tier affair.

"It's right up there among our best results ever," said Gregor Townsend afterwards. "This was a tough place to come and win. It wasn't our best performance, but it certainly showed a lot of courage and defensive endeavour."

Those qualities were never more important than just after the interval when Montpellier, crushingly disappointing in the first half, finally got up a head of steam. By that stage, Glasgow had already been disrupted by the loss of Tommy Seymour, knocked out cold in a gruesome clash of heads with Sitaleki Timani, and the withdrawal of Alex Dunbar, who was feeling the effects of the leg injury that had kept him out for a few weeks beforehand. In short, Glasgow looked vulnerable.

But they managed the period brilliantly. Granted, they rode their luck at times - their luck including Montpellier's laughably bad handling as well - but their defence was outstanding. Montpellier had a series of set-pieces deep in the Glasgow 22, but were kept out every time. The Warriors survived the passage without conceding a further point.

Indeed, they even broke out brilliantly to all but tie up the win. Mark Bennett made a wonderful, weaving run that was only stopped a few yards short of the posts. Robert Ebershorn was yellow-carded for killing the ball at the ensuing ruck, Finn Russell hammered over another penalty, and Glasgow's 9-6 lead suddenly looked a lot healthier for the addition of another three points.

And it acquired a glow soon afterwards when Russell landed his fifth penalty to take the scoreline to 15-6. At that point, with around 15 minutes left, Montpellier seemed caught in two minds as a stream of penalty awards came their way. Should they press for victory or try to secure the bonus point? In the end, they only just scraped the latter.

Russell can be proud of a contribution which saw him score all Glasgow's points, but his all-round game management was just as important during a first half in which Glasgow were by far the tidier side. There were more heroes, still, in the pack. The Glasgow tight forwards put in an immense shift against a group of French forwards renowned for their power and size. Time and again, Montpellier tried to get their driving maul going, but Glasgow never allowed it to gather momentum.

Josh Strauss had another huge game at the back of the scrum, while Tim Swinson and Jonny Gray stood up superbly in the second row. Euan Murray rolled back the years, playing for all but the last few seconds before Rossouw de Klerk replaced him.

Glasgow also had the satisfaction of hearing one of the most beautiful sounds in rugby: a French crowd giving their own team grief. It began early when it was clear Montpellier were struggling to string more than two or three phases together.

Glasgow took advantage with Russell kicking penalties in the second and 12th minutes. Montpellier scrum-half Benoit Paillaugue replied with one of his own in the 15th minute, but Russell added another to take things to 9-3 a few moments later.

Paillague scored again before the break, but by then the pattern was set. Glasgow were stretched in defence, but their composure got them through. A December double-header against Toulouse is the next item on their European menu, and they will approach it in confident mood.