If this was another tame return after a violent first leg then expect today's rematch in front of the European Rugby Cup Board of Directors in Dublin to be a bit more emotive.
The two clubs will hear later today if sanctions are to be taken against them in the wake of their stormy Pool E match in the Heineken Cup two weeks ago.
Fines along the lines of those already imposed on Brive and Pontypridd - pounds 30,000 each with half suspended against their future good conduct - looks certain.
The tournament director, Roger Pickering, suggested to his board they take sanctions against the clubs after interviewing them last week. He spent his weekend in Wales watching the tournament's bad boys in action at Pontypridd and Llanelli and was delighted to witness massive outbreaks of peace.
"The tournament is back on track after two good matches. I think everyone has got the message and rugby has come out on top this weekend," he said.
Casting his mind forward to today's disciplinary hearing, Pickering sent out a clear message to both clubs as to their likely fate.
"I think the violence in the match between Pau and Llanelli was equally as serious, if not more so than in Brive. There was more gratuitous violence and, on balance, I think it was worse than in Brive," Pickering added.
For the cash-strapped Scarlets, who were recently forced to sell off Stradey Park to the Welsh Rugby Union for pounds 1.25m to help balance their books, any fine could prove disastrous. As far as their coaching director, Gareth Jenkins, is concerned, it would also feel unjust.
"It seems as though we are going to be heavily reprimanded and fined. Unfortunately it is going to cost us dearly financially for retaliating," Jenkins said.
"A heavy fine would make us feel hard done by because of poor refereeing.
"It was absolute thuggery what their scrum-half Frederic Torossian did out there. He was involved in five incidents, including butting Neil Boobyer and Frano Botica and kicking Rupert Moon.
"I don't think this player will play in the tournament again after Monday's hearing."
Ironically, it was a try by Moon, Torossian's opposite number, which eventually won the day for Llanelli. He struck midway through the first half to round off a great break by Chris Wyatt and three Botica penalties did the rest.
It was the first defeat for Pau in the tournament, although they still head Pool E on points difference from the Scarlets.
Llanelli: Try Moon; Penalties Botica 3. Pau: Try Dantiac; Conversion Aucagne; Penalties Aucagne.
Llanelli: D Williams; G Evans, N Boobyer, S Jones, M Wintle; F Botica, R Moon; R Jones (A Jones, 75), R McBryde (capt), H Williams-Jones, S Ford, M Voyle, A Gibbs, I Jones, C Wyatt.
Pau: N Brusque; B Lhande, D Dantiacq, F Leloir, Y Martin; D Aucagne, F Torossian; P Triep-Capdeville (S Bria, 75), J Rey (capt), J-M Gonzalez, A Lagouarde, T Mentieres, S Keith, N Bacque, F Rolles (A Agueb, 68).
Referee: B Stirling (Ireland).