Brock James landed a crucial late penalty as Clermont battled back to defeat Harlequins 16-13 at The Stoop in Pool 4.
Harlequins had embarked on a comeback of Lazarus proportions when they defeated Racing MÃ©tro in Nantes, seeking to go from losing their first two matches of the pool to qualifying for the knockout stages.
No one has done it before and Harlequins for some time in this match looked like the first to break new ground in the competition, but it was not to be.
Two tries in the second half from Clermont's wingers, Napolioni Nalaga and Sitiveni Sivivatu, proved decisive as Harlequins remained scoreless after the break.
Clermont's rapid start, with Nalaga getting behind the defence, ended in a chip shot for James on the Harlequins' 22 with only two minutes up on the clock to put the visitors ahead.
Harlequins though edged the early physical confrontations, with young Will Collier winning a scrum penalty that lead to Clermont being pinged at the resulting lineout. Evans was unable to convert the resulting shot at goal.
Nalaga then coughed up a gilt-edged chance in acres of space trying to bring in James' cross-field kick, an opportunity the Fijian would usually be expected to devour.
Damien Chouly's absence in the eight shirt was hardly felt by Clermont due to a pummelling opening fifteen minutes from Fritz Lee. But then he dropped a simple pass when put through by James - Harlequins continuing to ride their luck in the opening quarter.
The way Clermont were beginning to control the scrum and the physical battle, Harlequins needed something special to reverse the tide and it duly came.
Chris Robshaw's chip down the left touchline was reached by Danny Care, who brilliantly flicked the ball inside before it fell into touch for Hopper to scamper home.
Evans had better success with his second penalty attempt from 45 metres out to stretch the lead to 10-3, but he nearly had more when he cut through a gap presented by Davit Zirakashvili and surged towards the Clermont 22. It ended in a penalty which the former All Blacks number ten duly converted.
The visitors performance grew increasingly shaky, botching a five-metre lineout opportunity before the interval after the returning AurÃ©lien Rougerie spilled a simple pass on his 50th Heineken Cup appearance. It meant that Harlequins lead by ten at half-time.
Harlequins had taken their chance in the first half but when Brown's foot stuck in the mud he was forced to watch Nalaga race towards a kicked-through ball as Clermont pounced. The wing hacked on and beat Care to the bounce to bring the Pool 4 leaders back into the match.
Effort was certainly not at a low level from either team, but each time an attack began to build the momentum the opposition defence would rise to snuff it out - such is the quality of these two sides.
Harlequins went off their feet to hand James a shot at goal, but the fly-half sacrificed accuracy for distance with his attempt to keep Clermont five points down.
Jean-Marcel Buttin continued to keep the hosts honest with a couple of searing breaks from full-back, justifying his big reputation in the process.
Buttin's style certainly suited the final quarter's style as the tempo quickened and Harlequins grew cagey protecting their lead, but two penalties for obstruction halted Clermont's attacks.
Evans had a chance to allow some breathing space and crucially put Clermont out of losing bonus point range, but his kick fell wide to increase the rising tension.
Clermont capitalised. A series of drives from their pack sucked in the defence and allowed the space for Sivivatu, leaving at the end of the season for Castres, to dot down in the right corner and bring the French side level. James though, once more, couldn't make his kick count to leave the scores at 13-13.
When presented with a far simpler chance though minutes later right in front of the posts, James made no mistake.
Harlequins weren't out of chances, a five-metre lineout getting the crowd to their feet, but Dave Ward's throw when it mattered wasn't straight.
A turnover at the scrum kept their hopes alive once more but Clermont's choke tackle, just as they suffocated Harlequins in key areas throughout the second half, was the decisive blow. It was a brave performance from the English side, but their surge in the competition was cruelly cut short.
Pens: Evans 2
Tries: Nalaga, Sivivatu
Pens: James 2
Harlequins: 15 Mike Brown, 14 Charlie Walker, 13 Matt Hopper, 12 Tim Molenaar, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (capt), 6 Luke Wallace, 5 George Robson, 4 Nick Kennedy, 3 Will Collier, 2 Dave Ward, 1 Joe Marler.
Replacements: 16 Joe Gray, 17 Mark Lambert, 18 Paul Doran-Jones, 19 Charlie Matthews, 20 Tom Guest, 21 Karl Dickson, 22 Ben Botica, 23 Ollie Lindsay-Hague.
Clermont: 15 Jean-Marcel Buttin, 14 Sitiveni Sivivatu, 13 AurÃ©lien Rougerie (capt), 12 Wesley Fofana, 11 Napolioni Nalaga, 10 Brock James, 9 Morgan Parra, 8 Fritz Lee, 7 Alexandre Lapandry, 6 Julien Bardy, 5 Nathan Hines, 4 Jamie Cudmore, 3 Davit Zirakashvili, 2 Benjamin Kayser, 1 Thomas Domingo.
Replacements: 16 Ti'i Paulo, 17 Vincent Debaty, 18 ClÃ©ment Ric, 19 Julien Pierre, 20 Gerhard Vosloo, 21 Ludovic Radoslavjevic, 22 Mike Delany, 23 Benson Stanley.
Referee: John Lacey (Ireland)
Assistant referees: Gary Conway (Ireland) Brian MacNiece (Ireland)
Television match official: Simon McDowell (Ireland)
by Ben Coles