Clermont followed up on their rare victory at Munster with an impressive 26-19 victory at home over the Irish province in the European Champions Cup on Sunday.
The Top 14 side stunned Munster last weekend at Thomond Park, winning 16-9, and their latest back-to-back triumph moved them atop Pool 1 (14pts), one ahead of Saracens, who were 28-15 victors over winless Premiership rivals Sale on Saturday.
Qualification for the knock-out stage will be a challenge for two-time former champions Munster, sitting in third in the pool on 10 points thanks to a last-minute Ian Keatley penalty that handed them a bonus defencive point.
The Irish have a trip to Saracens to come before rounding off with a home game against Sale, while Clermont are away at Sale before welcoming Saracens to Stade Marcel-Michelin.
There was bad news for Ulster, however, as they went down 22-13 at Scarlets, for whom Rhys Priestland kicked 17 points alongside James Davies' late try.
It was Scarlets' first ever win over Irish opposition in 12 European games and the result moved them into second behind Toulon, Saturday's 23-8 victors over Leicester, who like the Llanelli outfit also have eight points but are in third on points difference.
In Clermont, Munster fly-half Keatley kicked two early penalties, but the home side hit back with a fine team try set up by a Wesley Fofana break with support from prop Thomas Domingo and Morgan Parra, skipper Damien Chouly driving over from close range.
Camille Lopez missed the extras but hit a 26th minute penalty before handing over to Parra for a long-distance three-pointer.
Parra's effort just before half-time fell well short, but a poor clearance saw former France captain Aurelien Rougerie haring back down the wing.
Munster full-back Felix Jones did well to haul the centre down, but the Irish side's clearing kick was again quickly recycled and found its way to Fijian winger Noa Nakaitaci, who spotted a gap and proceeded to step his way through the defence and stretch over the whitewash for a fine individual try.
Lopez was successful with the conversion to leave it 15-6 at the break, Keatley kicking a third penalty just into the second period to keep Munster in the game.
Welsh referee Nigel Owens then sin binned Felix Jones after his cynical raising of a knee into Lopez as the Clermont fly-half went to chase his own kick ahead.
Lopez compounded Irish concerns by kicking the resulting penalty and added another in the 58th minute after some hard-hitting defence in midfield paid off, the Irish guilty of holding on too long in the tackle.
Clermont No 8 Fritz Lee knocked on over the Munster line as the French team turned the screw, Chouly eventually crossing for his second try after latching on to a pinpoint cross-kick by Lopez and riding Simon Zebo's tackle.
Munster's Duncan Casey scored a late interception try converted by Keatley, who then kept his nerve to nail the all-important penalty to gift his side a point.
Earlier in the day, Wasps put themselves right back in the mix in Pool 2 when they ran out 44-17 winners over Castres in their last home match at Adams Park before their move to Coventry's Ricoh Arena.
Source: AFP