Leinster's Ireland internationals warmed up in style for the Six Nations by demolishing a Dragons side missing eight current Wales squad members.
Leinster (27) 55
Tries: Gissing, Horgan (2), Contepomi, Hickie (2),
Cons: Holwell (7)
Pens: Holwell (2)
Dragons (3) 3
A 10-minute purple patch just before half-time saw tries from Ben Gissing, Shane Horgan and Felipe Contepomi.
Horgan's second earned Leinster their bonus point with Denis Hickie (2) and Niall Ronan adding further scores and David Holwell kicking 20 points.
Third-place Leinster now lead the Dragons and Scarlets by seven points.
The home side dominated possession in the opening stages but could make little headway early on with David Holwell's penalty the only score of the first quarter.
A rare attack from the Dragons saw Sione Tuipulotu knock on with Gareth Wyatt clear outside him, but the visitors levelled with a Montgomery penalty.
The opportunity arose when a fight between Chris Anthony and Ben Gissing bizarrely ended with would-be peacemaker Holwell penalised.
Howell's second penalty quickly restored the home advantage before Leinster cut loose before half-time.
Gissing rumbled over from a five metre lineout on 33 minutes before Contepomi and Gordon D'Arcy combined to send Horgan racing in.
Then in injury-time, a Guy Easterby break saw the Dragons defence at panic stations with lock Neil Edwards yellow carded for killing the ball.
Leinster opted for the scrum five and a Holwell grubber kick saw Contepomi gather easily the score.
Holwell added his third conversion to make it 27-3 at the break.
It took Leinster just five minutes to clinch the bonus point with Holwell's cross kick allowing Contepomi to put Horgan over for his second, though the wing then went off as a precaution following an ankle knock.
On the other flank Denis Hickie got into the action with a close range try following a powerful D'Arcy break, while flanker Niall Ronan showed his skills with a chip and chase for the sixth.
The final quarter then saw multiple substitutions as Leinster pulled off many of their internationals while the Dragons looked to stem the damage with fresh legs upfront.
But Hickie raised the half century on 69 minutes with his second from broken play with the immaculate Howell adding his seventh conversion for a personal tally of 20 points.
The result provided the Irish province with their biggest winning margin in the league and the Dragons with the worst defeat of their two-year existence.
Leinster: Dempsey, Horgan, Contepomi, D'Arcy, D. Hickie, Holwell, Easterby, Corrigan, S. Byrne, E. Byrne, Gissing, O'Kelly, Potts, Ronan, Miller.
Replacements: Nebbett, D. Blaney, McCullen, Costello, O'Riordan, Quinlan, Lewis.
Newport-Gwent Dragons: Tuipulotu, Wyatt, Montgomery, Winn, Breeze, Warlow, Baber, Snow, Richards, Anthony, Edwards, Sidoli, Ringer, Oakley, Forster.
Replacements: Chapman, Payne., Ireland, Black, Crawford, Thomas, Veater.
Referee: David Changleng (SRFU)