Blues feed off criticism to show they can still live with the big boys
They didn't flow like they once did, but the fight and determination Leinster showed in Marseille shows that talk of their demise may be decidedly premature.
Toulon remain kings, but the foundations on which their empire is constructed shook to the core by the Cote d'Azur as a Leinster team driven by a lack of affection from their own performed resolutely, without getting over the line.
Add Johnny Sexton to the mix and there is reason to be cheerful about next season, even if their dreadful Guinness Pro12 campaign will leave them further down the mountain starting off.
If they are to get back to the top table, then they'll need plenty of work but the performance should quieten any talk about Matt O'Connor's future and serve as evidence that they can live with the best.
"We'd always had a positive mindset coming into this match, it was other people writing us off and it played into our hands a little bit," scrum-half Isaac Boss said.
"We played the first half pretty smart, there were one or two errors let them back into it; not too much they did but our errors let them back in but it was a close-fought encounter.
"It was a weird old match, the way it went. It was tough conditions in the first half but we played it well, we had them doubting themselves and under pressure.
"There were times during the second half we could have had them under a lot more pressure and they could have folded, but they managed to stick in there."
Certainly, Toulon were not of a mind to underestimate the three-time champions.
"Leinster turned up, didn't they? I mean, they turned up and they played and they bashed us and we bashed them," said their former All Black second-row Ali Williams.
"It was tit for tat really and I think it just shows what a great competition and what great sides there are in Europe. The fact that Leinster came from last season's quarter-final and then come here and do that, and they almost won, let's be honest."
Man of the match Leigh Halfpenny will be glad that's the last Irish team he'll face this season, given that his previous encounter with most of the Leinster team came in a slug-fest in Cardiff.
"That intensity and physicality was right up there with an international match, very tight like it was against Ireland and it was touch and go throughout the game, back and forward," he said.
"Rugby games at times are decided by tight margins and as it went on you felt it would be decided by a couple of points, so every second, every minute of the game you had to be concentrating.
"If we switched off for one second it could have cost us the game but credit to the boys, especially having gone a man down, it was an immense feeling to get the victory."
They march onward to face Clermont and Leinster have a long time to lick their wounds.
They'll do so in the comfort that they can still live with the big boys and hope that the return of their king can bring them up to the required level.