Wasps (10) 13
Tries: Varndell 2 Pens: Walder
Scarlets (12) 18
Pens: Priestland 6
Varndell's brace of tries proved to be in vain
The boot of Rhys Priestland proved decisive as Scarlets chalked up their fourth successive victory with a hard-earned win over Wasps in the LV= Cup.
The fly-half kicked six penalties and his side had posted nine unanswered points before Wasps finally got going.
Tom Varndell latched on to Dave Walder's pass to score before holding off Daniel Evans for a second as his side cut the lead to two by the break.
But Walder landed just one of five attempts at goal to leave them adrift.
The Welsh side can guarantee a semi-final place with a bonus-point victory over Cardiff on 6 February, while Wasps have to hope that Harlequins fail to win against London Irish on Sunday if they are to stay top of Group C.
Wasps: Wallis, Varndell, Jacobs, Kefu, Lemi, Walder, Fury, Taulafo, Ward, Broster, Veale, Leo, Worsley, Matthews, Hart.
Replacements: Smith for Wallis (70), Mitchell for Varndell (64), Honeyben for Fury (41), Baker for Broster (63), Ellis for Hart (9). Not Used: Lindsay, Bocca, Odejobi.
Scarlets: Evans, L. Williams, Maule, Higgitt, Fenby, Priestland, Knoyle, John, Rhys, Manu, Reed, Welch, McCusker, Edwards, Turnbull.
Replacements: Newton for Maule (79), King for Higgitt (50), Phillips for Rhys (50), R. Thomas for Manu (50), Pugh for Edwards (61). Not Used: I. Thomas, Cooper, Ajuwa.
Ref: Dean Richards (RFU).