Scarlets (10) 17
Waters crosses for the opening try at Stradey Park
Tries: Easterby, M Jones
Cons: S Jones (2)
Pen: S Jones
Wasps (19) 33
Tries: Waters (2), Skivington, Cipriani, Flutey
Cons: Cipriani (4)
Holders Wasps made a powerful Heineken Cup statement with a thumping bonus point win at Stradey Park, leaving the Scarlets facing a group-stage exit.
A woeful first half defensive display from the home side saw the outstanding Fraser Waters score two tries and help create the third for George Skivington.
The Scarlets got a Simon Easterby try and exerted early second-half pressure.
The Wasps defence held out, and Danny Cipriani and Riki Flutey completed the rout before a late Mark Jones score.
After an emotional tribute to Llanelli and Wales legend Ray Gravell, whose funeral was held at Stradey Park this week, the visitors took an early grip on territory and possession.
Man-of-the-match Waters was providing the main cutting edge, and when Matthew Watkins missed his man in midfield Waters got the first try, spinning out of Morgan Stoddart's desperate cover tackle.
The centre profited again five minutes later after Cipriani's chip to the corner took a wicked bounce and was flapped at by Stoddart.
We're growing as a group and have taken on harsh lessons here
Scarlets director of rugby Phil Davies
Simon Shaw was on hand to gather the loose ball, and the England lock gave a delightful inside off-load out of the tackle to gift Waters a simple score.
Dwayne Peel's quick thinking got the Scarlets back into the game, tapping and going as Wasps complained about a penalty at the scrum.
After a sniping run he found Mark Jones, the winger passing inside to skipper Easterby who strolled in under the posts.
But the visitors immediately struck back from first-phase ball, Cipriani passing inside to the irrepressible Waters, whose jinking run tore the defence open.
He found the supporting Skivington, who brushed aside Watkins to romp home.
Stephen Jones pulled back a penalty to make it 19-10 at the break, the visitors lucky to stay at 15 men after some cynical defensive work.
The Scarlets began to get their momentum going after half-time only to be held out by superb defensive work, a Paul Sackey tackle on Gavin Thomas particularly notable.
We'll go to Clermont Auvergne confident that we can turn them over
Man-of-the-match Fraser Waters
When the visitors got possession together they looked threatening, but the decisive score was controversial.
Cipriani was tackled well short of the line but was not held, the fly-half rising and extending a telescopic arm to ground the ball.
After debate the officials correctly ruled on the grounding for a bonus-point score, but the Scarlets claimed that Waters had blocked potential tacklers in an accidental offside beforehand.
With Scarlets spirits shattered the impressive Flutey had a field day, and was rewarded with the fifth try after a powerful, pacy run.
Mark Jones got a consolation score for the Scarlets in the closing minutes, handing off at a ruck and showing the pace to run in from 40m.
But to compound the home side's misery, Watkins was helped off near the end with a worrying looking leg injury.
Scarlets director of rugby Phil Davies:
"We created opportunities but lacked Wasps' clinical edge, they were persistent and accurate and there are no complaints.
"We knew that they were a quality team, they're the champions and have been putting together those sort of performances for years.
"We're growing as a group and have taken on harsh lessons here, we'll move on in the next couple of weeks.
"It's a tough group with four quality teams. We know we have to get points on the board against Munster, but we can score and create problems."
Man-of-the-match Fraser Waters:
"[Coach] Shaun Edwards had a go at us in midweek because of our poor starts so we knew we had to come out fast to set up the game.
"Playing alongside Riki Flutey has been a great help for me with the line breaks he makes.
"After a poor opening in the league we've been picking up momentum and we hope that the performances over the last couple of weeks have moved us on.
"We're in one of the toughest groups, but we've got two wins and will go to Clermont Auvergne confident that we can turn them over."
Scarlets: Stoddart, M. Jones, King, G. Evans, Watkins, S. Jones, Peel, I. Thomas, Rees, Manu, Cooper, MacLeod, Easterby, G. Thomas, Popham.
Replacements: Daniel for Watkins (80), Priestlend for S. Jones (80), L. Davies for Peel (80), Hayter for Rees (17), Eustace for Cooper (72), N. Thomas for Popham (72). Not Used: Douglas.
Wasps: van Gisbergen, Sackey, Waters, Flutey, Voyce, Cipriani, Reddan, Payne, Ibanez, Adams, Shaw, Skivington, Hart, Rees, Dallaglio.
Replacements: Lewsey for Waters (72), Walder for Flutey (75), Amor for Cipriani (73), Holford for Payne (77), Ward for Ibanez (48), Birkett for Shaw (60), Haskell for Dallaglio (58).
Referee: Alain Rolland (Ireland)