Jordan Larmour and Fergus McFadden scored a brace apiece as six-try Leinster crushed Ulster 38-7 at the RDS.
The hosts led 12-0 at half-time following scores from Barry Daly and Larmour as Ulster consistently turned the ball over when well placed.
Leinster were guilty of wasting some opportunities themselves but, inspired by the irrepressible running of 20-year-old Larmour, Leo Cullen's men cut loose after the break to score further tries through Larmour, McFadden (2) and replacement Johnny Sexton.
Jacob Stockdale's try was a mere consolation for Les Kiss, who will be under renewed pressure after a second derby thrashing in three games.
A lovely sidestep from McFadden set up the opening try for the hosts after just six minutes.
McFadden took out Andrew Trimble then swerved inside and fed Larmour on his shoulder, who beat Stockdale to touch down. Ross Byrne followed up with the conversion.
Jordan Larmour simply can't be stopped right now 😵
— PRO14 RUGBY (@PRO14Official) January 6, 2018
Five minutes in and he opens the scoring for @leinsterrugby with a delightful sidestep before going over 👏
Catch the action LIVE on @SkySportsRugby, @TG4TV and @BBCSPORTNI#LEIvULS #GUINNESSPRO14 pic.twitter.com/QsZnxYWsTu
Ten minutes later, Leinster had their second. Daly held off Charles Piutau far too easily to touch down in the left corner, this time unconverted, and the hosts looked set to build a big first-half score.
That didn't materialise as they wasted several good scoring opportunities but Ulster couldn't make their possession count either - they were turned over four times near the Leinster line in the opening period.
Ulster also had a big let-off just before the break when Iain Henderson got back brilliantly to stop Larmour finishing a kick through from Byrne.
Leinster thought they had a third score shortly after the restart when Jamison Gibson-Park and Larmour combined brilliantly for the latter to touch down but it transpired that the scrum-half had been ahead of his colleague's initial kick in behind.
The early second-half pressure pays off for 🔵 @leinsterrugby.
— PRO14 RUGBY (@PRO14Official) January 6, 2018
Fergus McFadden receives the ball out wide, steps inside and dives in for Leinster's third try 👌
Watch it LIVE on @BBCSPORTNI, @SkySportsRugby and @TG4TV 📺#LEIvULS #GUINNESSPRO14 pic.twitter.com/aAFXT2Cotb
The let off was to be only temporary as McFadden hit Ulster with two quick tries.
In the 48th minute, Larmour chipped and gathered and Sean Cronin took it on well before the ball was spread wide to McFadden, who burned Stockdale with that familiar sidestep to score.
The 32-cap winger had his second six minutes later when Ulster once again turned it over on the Leinster line.
🚇 Andrew Porter is like a freight train and @ulsterrugby can't stop him 💪
— PRO14 RUGBY (@PRO14Official) January 6, 2018
The replacement breaks through and lays it off for @fergmcfadden's second try ✌️
It's all live on @BBCSPORTNI, @SkySportsRugby and @TG4TV 📺#LEIvULS #GUINNESSPRO14 pic.twitter.com/yzCA2jL5yP
Andrew Porter surged upfield brilliantly before offloading to Gibson-Park. The scrum-half fed McFadden to streak clear and secure the bonus with just under half an hour left on the clock.
Johnny Sexton came on for the final 20 minutes but Ireland coach Joe Schmidt will be sweating on the fitness of Garry Ringrose, who was forced off with a knee injury.
Leinster weren't finished yet as Larmour finished off a looping pass from Noel Reid for his second and Leinster's fifth try of the night before Ulster salvaged some pride with seven minutes to play.
Tommy Bowe burst through the middle and was brought down just before the line but McPhillips flicked an overhead pass for Stockdale to touch down. Bowe, who had only been on 20 minutes, was forced off with a shoulder injury.
As the clock ticked into the red, Ulster were well into double figures in terms of turnovers and another one saw them caught on the counter yet again.
Reid and Max Deegan both showed great hands to set Johnny Sexton free for Leinster's sixth try, which he converted to close out a comfortable 38-7 victory.
