Ulster secured second spot in Pool A with their fourth consecutive Champions Cup victory but a game that had little riding on it for the hosts was almost memorable for all the wrong reasons.
Leading 34-12 with 10 minutes to go, Ulster ended the game hanging on after three tries in the final exchanges for Clermont cut the lead to just three points at the death. It was a bizarre finale for Dan McFarland's men who came into the game already assured of their place in the last-16 after last week's away-day victory over Northampton Saints at Franklin's Gardens.
Back on their own patch, this visit from the Top 14 giants was all about seeding for the next round. Confirmation that Racing 92 were to be awarded a 28-0 win after their own clash with Northampton was cancelled due to Covid-19 cases in the English side's squad, second seeding and the potential for a home quarter-final was the prize on offer.
And while the thought of a last eight tie in Belfast remains some way off given the potential for facing reigning champions Toulouse over two legs in next April's first knock-out round, Dan McFarland will nonetheless have been heartened to see his side finish the pool stages as the first side to go four from four on the pitch despite such a late scare.
After last week's win set tongues-wagging about the quality of their back-line play, it was the forwards to the fore here with Rob Herring helping himself to a brace of tries via the maul and Duane Vermeulen also barging over from close range. Not to be outdone, Six Nations call-ups Mike Lowry and Robert Baloucoune would both cross the whitewash themselves before the late drama.
Clermont, the side in greater need of victory, struggled with discipline throughout and despite that final flurry the side now led by former Ulster coach Jono Gibbes looked resigned long before the final whistle to the reality that they'd be requiring help from elsewhere to make the knock-outs.
Having lost the reverse fixture at the Stade Marcel Michelin last month off the back of two yellow cards, their reading of the referee was no better in the early stages here.
Having allowed Ulster to escape their own territory when not rolling from the ruck, two further penalties in their own '22' allowed the hosts to get their usually potent maul rolling. While Morgan Parra signalled frantically for help, neither he nor the arriving Alivereti Raka could prevent Herring from burrowing over.
Fast starts have been instrumental to Ulster's winning run in Europe this season but, after Nathan Doak's conversion attempt came back off a post, they gave Clermont back three points off the restart when Eric O'Sullivan was trapped in the ruck and Parra duly knocked over the resulting penalty.
And the Ulster loosehead would be shaking his head ruefully again at the midway point of the first-half when Rabah Slimani earned a scrum penalty on Ulster's put in to allow Parra to kick his side into a one-point lead.
Clermont, though, like Ulster before them, made a mess of the restart, setting Ulster right back on the offensive.
Again Dan McFarland's men showed no hesitation in going for the corner over the posts. Again they got quick reward.
There was to be no maul score this time but, after Herring, Hume and Doak were all stopped short, Alan O'Connor filled in at scrum-half to get the ball out to Burns. The out-half wasted no time in getting the ball to man of the moment Mike Lowry, the full-back building on his brace last week as he rounded Parra on the outside to score.
But with both sides struggling to get to grips with referee Luke Pearce's demands at the breakdown, the boot of Parra would keep Clermont lurking and then, with five minutes before the turn, nudge them into their first lead.
They'd not carry the advantage to the sheds though, again undone by their own indiscipline, their eighth penalty of the opening 40 minutes proving to be the most crucial. Raka was binned on his own line as he tried to halt the charge of Ethan McIlory and, after a few prior line-up hiccups, the half would end as it started with Herring finishing forcefully from the base of the maul.
A Doak penalty when Clermont were caught in front of the kicker provided the first points of the second-half and offered some breathing room.
And before Raka would return to the fray, Ulster would have both the game and their try-bonus in hand.
Duane Vemeulen's first ever Ulster try was certainly well received by the near-capacity crowd and Doak's conversion made it 27-12.
Oddly for what was still in store, both sides seemed to then sense that Clermont's race was run and the dip in the performance of the visitors was met with an increased intensity from Ulster.
Starting to throw the ball around with a bit more abandon, the game opened up as the likes of Hume, Lowry and Baloucoune really began to enjoy themselves.
And it was the latter who got the fifth try. It was a great break from Lowry that had advanced the ball deep into Clermont territory and Ulster showed real patience to wait for a further opening to present itself. When it did, Billy Burns capped off a strong personal performance with a superb pass out to Baloucoune for the run in score.
Then the finale few could have anticipated.
First Jacobus van Tonder and Raka would both finish off fine Clermont moves with the growing sense of chaos ratcheting up a few more notches when Judicaël Cancoriet went over from a maul with three minutes to go.
Not until Balocoune smashed the same man into touch did any sort of order return with Ulster holding on for a win that had seemed all but wrapped up a mere ten minutes prior.
After Northampton had also been allowed back into a game that looked over a week ago, there will be no prizes on what Ulster will be working on ahead of the knock-out stages in the spring.
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