Sportal.co.nz 19.May.2013Getty Images
The first half at the Aviva Stadium was a tense battle, with both sides heading into the break locked at 3-3.
Napolini Nalaga and Brock James crossed for early tries in the second half for Clermont as they took a 15-6 lead.
But Toulon produced the bravest of late comebacks as the boot of Englishman Jonny Wilkinson and a try from compatriot Delon Armitage gave them a terrific triumph.
Clermont scrum-half Morgan Parra – the competition's leading scorer – and his Toulon counterpart, Wilkinson, traded early penalties in a largely cagey beginning in the Irish capital.
Clermont captain Aurelien Rougerie was dangerous and his side shaded proceedings in the first half, only denied the game's first try after 35 minutes by a video referee.
Fly-half James ran down the right wing before producing a clever chip and he stormed past Chris Masoe before diving on the ball and claiming a try.
It was a terrific move, but video replays showed the ball had been grounded on the dead ball line and no try was given.
Clermont did get their try early in the second half as the Heineken Cup's top try scorer this year, Nalaga, dived over superbly in the corner.
New Zealand winger Sitiveni Sivivatu started the move, winning a loose ball before finding Rougerie, and he fed Nalaga who was charging up the wing.
The Fijian kept his composure, skipping around a would-be tackler before crossing for the opener.
The resultant conversion was missed and Wilkinson kicked truly shortly after, reducing Clermont's lead to 8-6.
But their advantage grew again as James scored a truly sensational try.
The fly-half chipped over the Toulon defence and Rougerie chased it down and held off multiple tackles before offloading to James who went sprinting past.
Parra kicked a simple conversion shortly after to give Clermont a 15-6 lead as Toulon introduced trio Freddie Michalak, Jean-Charles Orioli and Joe van Niekerk in a bid to change the flow of the game.
Michalak was involved in Toulon's next score, with his chip leading to a penalty that Wilkinson converted, cutting the deficit to six.
And the match-defining moment came shortly after as Armitage scored the crucial try in the 65th minute.
A steal from Juan Martin Fernandez Lobbe released Armitage and he charged 35 metres up the wing to score his side's only try of the game.
The reliable Wilkinson kicked the conversion as Toulon hit the lead for the first time in the match and it was an advantage they did not surrender.
Clermont threw on David Skrela in the hope of a dropped goal that would have levelled the scores but ultimately, Toulon bravely held on, as Clermont were left to lament a disappointing finish to the second half.
The result was cruel on Clermont – who lost a thrilling semi-final to Leinster in the same competition last season – especially given the fact they headed into the final without a loss in all European Cup matches this campaign.
But Toulon – led by inspirational man-of-the-match Mathieu Bastareaud and World Cup winner Wilkinson, showing the form that saw him nominated for European Player of the Year – were just too good for their opponents.