Toulon director of rugby Bernard Laporte highlighted his side's defensive efforts following their Heineken Cup success.
The former France boss admitted to a moment of self-doubt after Clermont scored two early tries in the second half.
In a brutally physical clash even for a final, Laporte acknowledged the determination and bravery of his side's defence, particularly their tackling in the closing stages when clinging on to a slender lead.
"I could feel a lot of motivation in the room at half time but when they scored twice to go 15-6 up you do ask yourself questions," said Laporte.
"If they had scored again it would have been over but at the last ruck we managed to steal the ball and that was out advantage and the win.
"Clermont may have thought this is it, we have it, but they were not greedy or to sure of themselves.
"We defended superbly and never gave up. So there is tremendous joy at the victory and I congratulate the players, their performance was outstanding. At the beginning of the year there were some critics but they never see them going out not to give their best.
"They put all their hearts into defending, they showed the defensive quality of this team, and when Clermont targeted our forwards they responded well to that."