|Clermont Auvergne (11) 18|
|Tries: Fofana, Abendanon Con: Lopez Pens: Lopez 2|
|Toulon (16) 24|
|Tries: Bastareaud, Mitchell Con: Halfpenny Pens: Halfpenny 4|
A stunning solo try from Australia winger Drew Mitchell clinched a historic hat-trick of European titles for Toulon.
Camille Lopez kicked Clermont ahead and Wesley Fofana's try made it 11-3.
But Leigh Halfpenny's boot and a try from Mathieu Bastareaud put Toulon 19-11 up with half an hour remaining.
Clermont got within a point through a superb converted solo try from Nick Abendanon but Mitchell's brilliant riposte sealed a third straight title.
Toulon, fielding a galaxy of stars from around the rugby universe, had won the last two editions of the Heineken Cup and they knew victory in the inaugural edition of the European Champions Cup would see them become the first team to be champions of Europe three times in a row.
There was plenty of individual brilliance on show in red, with flanker Steffon Armitage again pushing his claims to be considered for England's World Cup squad despite playing abroad.
But ultimately the difference was as much down to Clermont's poor decision-making and errors under pressure, with the Vulcans prone to imploding at the worst possible moments at Twickenham.
Clermont, beaten by a solitary point by Toulon at the same stage two years ago, started the final in electric fashion and it took a brave one-on-one tackle from Bryan Habana to deny the rampaging Napolioni Nalaga before Jamie Cudmore lost the ball a foot from the line in a forest of bodies.
It was France fly-half Lopez who get the scoreboard ticking over and he landed a brace of penalties to one from Halfpenny to give Clermont a 6-3 lead.
Then came what looked like being a decisive moment. Sebastien Tillous-Borde's kick was charged down by Morgan Parra, his rival for the France scrum-half shirt, and Fofana was quickest to react.
The France centre had cover coming across but he had too much pace and dived over theatrically in the corner to give Clermont an 11-3 lead, with Lopez unable to add the conversion.
With the wind in their sails Clermont must have fancied their chances but a combination of their errors and Toulon's class and experience saw the champions claw their way back into the game.
Two Halfpenny penalties cut the gap to two and then Clermont's former England full-back Abendanon, who had a stellar tournament, made a poor decision, electing to chip as he mounted a counter-attack.
The ball only made it as far as Chris Masoe and the teak-tough New Zealander bounced off the Englishman before sparking a try-scoring 50m attack which ended with Bastareaud dummying before powering over from 10 metres.
Halfpenny converted and when Noa Nakaitaci foolishly threw the ball away after conceding a line-out, the Wales full-back was on target once again to give Toulon a 19-11 lead with half an hour to play.
Two Clermont mistakes had led to 10 Toulon points but they finally cut out the errors long enough to set up an epic last quarter.
When Habana kicked away a turnover Abendanon made amends for his earlier error, chipping cutely over the cover to regather and score.
Lopez's conversion meant the lead was suddenly down to a single point and it got even better for Clermont when Toulon lock Ali Williams was - perhaps controversially - ruled to have knocked on in trying to score.
But Toulon were determined to become the first side to be champions of Europe three times in a row and they sealed their unique treble when Mitchell exploded through a gap after a line-out and beat six Clermont defenders on his way to a dazzling try worthy of making history.
Clermont Auvergne: Abendanon; Nakaitaci, Davies, Fofana, Nalaga; Lopez, Parra, Debaty, Kayser, Zirakashvili, Cudmore, Vahaamahina, Bonnaire, Chouly, Lee.
Replacements: Delany for Nakaitaci (67), Rougerie for Nalaga (54), Radosavljevic for Parra (56), Domingo for Debaty (47), Ulugia for Kayser (63), Ric for Zirakashvili (66), Pierre for Vahaamahina (67), Bardy for Lee (54).
Toulon: Halfpenny; Mitchell, Bastareaud, J Hernandez, Habana; Giteau, Tillous-Borde; Chiocci, Guirado, Hayman, Botha, Williams, J Smith, S Armitage, Masoe.
Replacements: Wulf for J. Hernandez (66), Menini for Chiocci (48), Orioli for Guirado (63), Chilachava for Hayman (63), Taofifenua for Botha (47), Fernandez Lobbe for J Smith (58).
Not Used: Bruni, Michalak.