Quins winger Josh Freeman bagged a consolation try for the visitors, but a Llanelli victory was never in doubt. Giant-killers Banwen crashed 41-17 at home to Pontypridd, after trailing 34-3 at halftime. Five members of the Pontypridd backline were among the try-scorers, with fly-half Dai Flanagan scoring 16 points.
Beddau were brave, but had to bow 24-15 to a Bridgend side determined to finish the season with at least one piece of silverware. Former Pontypridd star Brett Davey kicked seven points for Beddau, but tries to Ravens backrowers Chris Davies and Dean Fitzgerald proved vital.
Aberavon took a surprise 18-0 lead over defending Premiership champions Newport, but there were several nervous moments when the Black and Ambers stormed back to 18-17 before time ran out.
Results - Konica Minolta Cup QF
Aberavon 18 Newport 17
Banwen 17 Pontypridd 41
Beddau 15 - 24 Bridgend
Llanelli 21 Carmarthen Quins 8
Llanharan 9 Llandovery 55
Newbridge 11 Pontypool 24