At half-time Leicester were heading out of Europe. Toby Flood had discovered a slice with his place-kicking, his team trailed by nine points and had looked shapeless and hesitant.
Clermont Auvergne, on the other hand, had been oozing menace and efficiency, with little Morgan Parra running the show from scrumhalf.
Welford Road was glum and growing glummer as the light began to fade and the rain to fall. It was as if pain was the trigger. Suddenly Leicester were a side transformed. Perhaps Richard Cockerill turned on a Scrooge special in the changing room and threatened all sorts of misery over the festive period if his team did not buck up.
First, though, a word on Clermont. They had been very polished and looked totally at ease in a place where many fear to tread. Parra had sat behind his all-consuming pack and dropped a goal to add to the one calmly landed earlier by David Skrela.
Their nonchalant classiness was disturbed when Julien Malzieu, a powerhouse on the wing with a slightly dodgy pair of hands, made a mess of the second restart after the drop-goals, and Leicester scored a soft try from the good territorial position.
Manu Tuilagi ran a cutback line straight from a scrum and Parra missed the tackle. For Clermont it was a soft, sloppy try; for Leicester, a lifeline to their fading European hopes.
Normal, imperious first-half service was resumed by the visitors when they swept on to a ball dropped by Martin Castrogiovanni and turned it into a try. Wesley Fofana was involved, as the centre had been in every positive piece of play.
Fofana took the stolen ball forward, supported by Alexandre Lapandry from the back row. From a ruck, the three-quarters did the rest, delivering the ball safely, and without a tackler left, to Sitiveni Sivivatu. Clermont were up on the board and cruising.
Then came the Leicester revival. Flood shrugged off two penalty slices and stroked the ball cleanly through the posts within a couple of minutes of the restart.
Ben Youngs, who had been as off-colour as his half-back partner, then darted between two big defenders and gave the ball smartly to the supporting Julian Salvi. This was more than just a reverse of form; Leicester were a point ahead.
Thomas Waldrom took them over the advantage line and when he had to scuttle back to retrieve a ball that might have bounced dangerously, the No 8 scooped it off the ground with one big hand and extinguished the threat.
Clermont were too good to allow themselves to be derailed so easily. Parra restored their lead with a second penalty, a kick that grazed a post on its way through. And Malzieu was then inches away from catching a crossfield kick from Brock James, who had come on for Skrela after 28 minutes.
But, unable to score, they were certainly in a different groove -- less rhythmic, more jolted. And Leicester have never actually been known for easing up when they have, as it were, an opponent by the throat. They squeezed a little harder and forced errors, Gerhard Vosloo, a shaggy South African, infringing on the floor.
Leicester might have scored a try when they regained possession and booted the ball down the centre of the field.
Hamilton led the pursuit, but chose to fall on the ball and look for the pass off the ground rather than keep the foot-rush going. It was not his day -- by that point in the match he had already dropped a pass and a kick and overrun a restart -- and the scoring moment passed.
Still, the feet of others were fully functional, and Flood knocked over another penalty after the Clermont pack lost its square shape at a scrum.
It sort of summed up the visitors' challenge. What had been perfectly formed in the first half was now a little wonky.
The destiny of Pool 4 would still appear to be in French hands. Clermont lost here, but gathered a bonus point, their third in total.
Leicester have yet to win one. Clermont have a chance to garner a fourth, plus a full set of win points, against Aironi in Italy, before they play Ulster at home. That will be the crunch, and showdowns at the Stade Marcel-Michelin tend to go only one way -- Clermont's.
Leicester have to go to Ulster and finish with the relatively easy home game against Aironi. By then it may be too late. Or maybe, as they proved to themselves today, it's never too late to turn things round.
Scorers -- Leicester: M Tuilagi, J Salvi tries; T Flood 3 pens, 2 cons. Clermont Auvergne: S Sivivatu try; M Parra 2 pens, con, d-g; D Skrela d-g
Leicester: G Murphy; H Agulla (J Hamilton 47), M Smith, M Tuilagi, A Tuilagi; T Flood, B Youngs; B Stankovich, G Chuter, M Castrogiovanni (D Cole 48); L Deacon, G Skivington; T Croft, J Salvi, T Waldrom
Clermont Auvergne: L Byrne; S Sivivatu, R King (G Williams 60), W Fofana, J Malzieu; D Skrela (B James 28), M Parra; L Faure (V Debaty 47), T Paulo (B Kayser 55), C Ric; J Cudmore, J White (N Hines 23); G Vosloo, A Lapandry, J Bonnaire
Referee: N Owens (Wal)
Sunday Indo Sport