Some of Leinster's more excitable fans were talking pre-match yesterday about a bonus point. And in a way they were right. What they hadn't reckoned was its value as a comfort to the hard landing suffered by the Heineken Cup champions in front of 48,964 in Lansdowne Road.
It was daft to think that they would run over the top of one of the pre-tournament favourites, and for more than 20 minutes here, on a disintegrating pitch but on a perfect afternoon for rugby, Leinster were trying not to win but to close the margin sufficiently to keep their hope of qualification alive.
The clock read 79.01 when Fergus McFadden delivered for them. And it may yet save Joe Schmidt's side. Three years ago, Northampton Saints came out of their pool as one of the best runners-up – on 19 points – and with two games to go, Leinster have the capacity to finish on 20.
"They're never gone," said Clermont coach Vern Cotter afterwards. Perhaps not, but they're really struggling. Richardt Strauss looks like his knee injury is long-term, while both Isa Nacewa (arm) and Shane Jennings (shoulder) are very doubtful for the spin to Belfast in the Pro12 on Friday night.
There's a bit of rugby still to be played in Europe, but for Leinster it will be done in pursuit of a runners-up spot, and with no margin for error. "Yeah, miracles happen in sport I guess," Joe Schmidt said of the task. "But mathematical long-shots seldom come to being. One of the things that I would say is that this team has done incredibly well for the last couple of years that I've been involved and even beyond."
There is a valedictory touch to the coach's comment, even if he isn't going anywhere for another season he doesn't think his team are going anywhere this term.
Clermont produced one of those performances that ticked every box you could think of, and they are virtually over the horizon. Asked if they could go on and win the whole thing, Cotter said: "We intend to. We'll do our best. Our intention is to go as far as we can, but there are some pretty serious obstacles."
It was a terrific game of rugby – well, it was until it became clear that the French were going home in style. Thereafter, Leinster's chase had a certain fascination, but the contest had changed fundamentally.
You may remember Cotter, after the first game, saying that they would go away and re-examine what Leinster had shown them in Stade Marcel Michelin, and figure out how to counter it. On the evidence of this, the Clermont coach didn't get much sleep this past week.
The high point of their defence was its use as a launch pad for attack. The pay-off came with half an hour gone and Leinster in possession around halfway, and asking all the questions. In fairness to the champions, they had come up with a whole heap of questions only to have them answered flat. So Heinke van der Merwe went for route one and took the ball up only to be drilled in the tackle.
Clermont poured forward with Sitiveni Sivivatu making a big bust out wide, finding Napolioni Nalaga on the touchline, and when he was hauled down in the corner by three blue shirts, Wesley Fofana struck off the ruck ball.
How pleasing that must have been for the centre, given his failure to close the deal in Bordeaux last season. Again the finish involved a reach, but this time he nailed it. Man-of-the-match Morgan Parra knocked over the extras and Clermont were 15-6 to the good.
It stayed that way until the break, and once they made it clear they weren't for turning in the third quarter, Leinster were doomed. For the first 40 minutes they had loads of ball, worked extremely hard to open up the Clermont defence, but got nowhere. Instead they had to settle for Jonny Sexton picking off penalties.
Sexton, aside from one chip that went out on the full, had a fine match and led from the front at times with a very physical showing. He managed to choke tackle Julien Bardy at one stage – no mean feat for a 10 on a flanker – but too often Leinster were looking for chokes, and conceding metres in the process, whereas Clermont were happy to chop. And they did a whole lot of that.
There was no weakness to their game, from set-piece to breakdown to the hard straight running of their big, powerful backs. And Parra was on hand to top it off whenever required, shooting a brilliant eight out of nine for 23 points.
He got them off to a good start after the break, only to be pulled back again by Sexton, but when Sean O'Brien was binned for an early tackle on Sivivatu, Parra struck again and with only 52 minutes gone Leinster were in desperate trouble. The scrumhalf pushed them out to 25-6 before Shane Jennings got over from a lineout maul on 66 minutes.
Parra tacked on another three points soon after however, and the full house was fairly quiet, aside naturally enough from the pockets of travelling fans. They weren't too put out by McFadden's late strike, but the home supporters will have been happy with it. If they understood its significance, that is. Still alive, but only just.
Scorers – Leinster: F McFadden, S Jennings try each; J Sexton 3 pens, con. Clermont: W Fofana try; M Parra 7 pens, con
Leinster: I Madigan; F McFadden, G D'Arcy, A Goodman, I Nacewa (D Kearney 59); J Sexton, E Reddan (I Boss 66); H van der Merwe (C Healy 47), R Strauss (S Cronin 12), M Ross (M Bent 62), L Cullen (capt), D Browne (D Toner h-t), S O'Brien (yc 51-61), J Heaslip, S Jennings (J Murphy 69)
Clermont: L Byrne (R King 37); S Sivivatu, A Rougerie, W Fofana, N Nalaga; B James, M Parra; R Chaume (V Debaty 66), B Kayser (T Paulo 70), D Zirakashvili (D Kotze 68), N Hines (L Jacquet 75), J Cudmore, J Bonnaire, D Chouly, J Bardy (yc 76)
Referee: W Barnes (England)