Scarlets scored three late tries to seal a convincing LV=Cup victory over the Tigers at Parc y Scarlets.
The home side were indebted to tries from wing Andy Fenby, full-back Gareth Owen and centre Nic Reynolds in the final 10 minutes which backed up seven penalties from outside-half Owain Williams.
Leicester were left frustrated after leading 19-15 at half-time with their cause severely hampered by the loss of two forwards, Fraser Balmain and Rob Andrew, to yellow cards during a tempestuous second half.
Williams opened the scoring with a penalty after seven minutes, but the lead was short-lived with No 8 Thomas Waldrom to becoming the game's first try scorer.
Scarlets hit back with three penalties from Williams before the hosts conceded a penalty try for collapsing a scrum and Cornwell converted to level the scores at 12-12. A fifth penalty from Williams made it 15-12 but Andy Forsyth's try put the Tigers in front at the interval.
The home side's positive start to the second half was rewarded with two more penalties from Williams and the momentum then swung decisively in Scarlets' favour when lock Andrew was sin-binned for tipping at a line-out with Balmain following him off shortly afterwards.