Beaten 2013 Heineken Cup finalists Clermont Auvergne took a significant step towards a place in this season's knock-out stages with a bonus point win in dreadful conditions in Llanelli.
A try in 34 seconds by wing Napolioni Nalaga began their effort, but after a superb Gareth Maule response the hosts were a clear second best.
Clermont added a scrum penalty try and Fritz Lee also went over.
Nalaga finished off with his sixth try in two seasons against Scarlets.
The opening whistle had barely been blown when Nalaga caught Thierry Lacrampe's chip kick to go over unopposed for Delany to convert.
After their 32-11 defeat in the first leg seven days earlier in France
But after the hosts fought back to take the lead by the break, Clermont's strength in depth proved too much for the west Wales region, with the visitors' scrum and driving play ensuring increased forward dominance as the game wore on.
And while the Welsh region again battled to the end, will be able to look back on a grim afternoon's work well done.
Harlequins host Racing Metro in the other Pool Four game on Sunday. Whoever wins that, with Racing seeking revenge for their humiliation at previously winless Quins' hands last weekend, will be the challengers Clermont should most fear in rounds five and six in January.
Scarlets have a mathematical hope of overhauling Clermont, but would have to take bonus point wins in their remaining two games and hope Saturday's opponents slip up twice in the New Year - on the evidence at Parc y Scarlets that scenario seems unlikely.
After Nalaga's opener Rhys Priestland put his side on the scoreboard as he and his team-mates set about underlining Easterby's confidence in them.
A bout of hostilities that ended with visiting skipper Aurelien Rougerie sin-binned in the 22nd minute gave the hosts a one-man advantage and their confidence gained a further boost when Priestland sent Wales centre Scott Williams haring out of his 22 to set up a wonderful Scarlets try.
Williams cut infield and after Liam Williams gathered Scott Williams' loose pass, Priestland provided the link to send centre Maule over.
Priestland followed his conversion with a penalty but Delany's reply left Clermont trailing by only three points at the break.
Brock James took over from Delany early in the second period, but the former found the swirling wind and rain not to his liking as he missed 45m and 35m shots from in front of the posts.
Clermont made up for James's misfortune by dominating a series of close-range scrums, which ended with English referee Wayne Barnes awarding a penalty try.
James added the conversion and after Lee drove over for a score confirmed by television English match official David Grashoff, the visitors set about seeking the fourth try.
Nalaga underlined his role as Scarlets' tormentor in chief, coming in off his wing on a powerful burst to defy Priestland and Scott Williams's challenges and official Grashoff again awarded the score.
Scarlets: Liam Williams; Nick Reynolds, Gareth Maule, Scott Williams, Jordan Williams; Rhys Priestland, Gareth Davies; Phil John (capt), Ken Owens, Samson Lee, Jake Ball, George Earle, Josh Turnbull, Rob McCusker, John Barclay.
Replacements: Rhodri Williams for G Davies (68), Rob Evans for John (60), Emyr Phillips for Owens (68), Rhodri Jones for Lee (68), Richard Kelly for Ball (60).
Not Used: Johan Snyman, Aled Thomas, Adam Warren.
ASM Clermont Auvergne: Jean-Marcel Buttin; Sitiveni Sivivatu, Aurelien Rougerie (capt), Regan King, Napolioni Nalaga; Mike Delany, Thierry Lacrampe; Thomas Domingo, Benjamin Kayser, Clément Ric, Jamie Cudmore, Julien Pierre, Julien Bonnaire, Julien Bardy, Damien Chouly.
Replacements: Noa Nakaitaci for Rougerie (74), Brock James for Delany (47), Ludovic Radosavljevic for Lacrampe (22), Raphael Chaume for Domingo (68), Vincent Debaty for Kayser (64), Ti'i Paulo for Ric (64), Fritz Lee for Bardy (50), Hines for Cudmore (60).
Sin bin: Rougerie (21).
Referee: Wayne Barnes (England)
Assistant referees: Matthew Carley, Nigel Carrick (England)
TMO: David Grashoff (England)