All five Welsh sides in the Heineken Cup lost, with Leinster scorching in for 30 points in the opening 36 minutes, including two tries to wizard centre Brian O’Driscoll and two to winger Gordon D’Arcy.
Swansea fought for respect in the second half but were never in with a chance of victory. D’Arcy completed his hat-trick in the final minutes and his conversion took the Irish province past the 50-point mark.
Swansea have now conceded 160 points in their past three matches, and have young gun Gavin Henson on the sideline with a three-match WRU ban for his red card against Llanelli.