Leinster are set for a United Rugby Championship semi-final clash against the Bulls after accounting for Ulster at the Aviva Stadium.
The prize for their 23-point victory over the visitors is a trip to Loftus Versfeld next Saturday to take on the side that beat them in the 2022 semi-final.
Earlier in the day, the Pretoria side scraped past Benetton 30-23.
Leo Cullen started with 12 of the side that began their Champions Cup defeat two weeks ago and their strength in depth told against a depleted Ulster side in front of 18,174 at a sunny Aviva Stadium.
First-half tries from Robbie Henshaw and James Lowe had Leinster in control by the half-hour mark, and while Dave McCann, Stewart Moore and Mike Lowry scored for Ulster they were mere consolations.
Lowe, Jordan Larmour, Josh van der Flier and Ross Molony all crossed in the second half as Leinster recorded their sixth URC play-off win in a row over Ulster.
Having served up two cracking contests in the regular season, both won by Ulster, the opening half was a largely insipid affair that lacked any intensity.
Ulster had their moments, notably from Cormac Izuchukwu but after the lock was forced off with a head injury in the 19th minute, the fizz left the team, who were already without regular second rows Alan O'Connor and Kieran Treadwell.
Nick Timoney was only denied a try by a brilliant Joe McCarthy tackle and that was as close as they got in the first half.
Having failed to captialise on that spell of pressure, during which Will Addison and Billy Burns, both playing their final games for the province, were causing problems, Ulster struggled to find any cutting edge.
Leinster's lineout was off but with Caolan Doris punching holes in midfield and Jimmy O'Brien's quick feet, the hosts had Ulster scrambling.
But the breakthrough didn't arrive until the 19th minute when Tadhg Furlong found space in midfield and fed Jamie Osborne.
The centre had a two-on-one but failed to send Jamison Gibson-Park in for a run-in. However, Moore's tackle didn't halt Osborne and he had Henshaw (above) in support for an easy score, which Byrne converted.
Soon Ulster's indiscipline began to tell and after man of the match McCarthy won a jackal penalty, Addison went high on Byrne under the posts and the out-half made it 10-0.
Lowe (below) took Byrne's inside pass on the 22 before beating two poor Ulster tackles for their second try in the 31st minute, Leinster painting by numbers in the Dublin 4 sunshine.
Richie Murphy's side earned a couple of penalties in the 22 before the half-time whistle and felt slightly aggrieved that they didn't work a score and Leinster got in 17-0 up at the break.
Ulster did have the first say of a livlier second half when John Cooney struck over a penalty; Henshaw was caught offside following a Garryowen that Leinster failed to deal with.
Leinster hit back immediately when O'Brien switched the play in midfield to a reverse pass to Byrne. The Ireland out-half jabbed a kick across the field and Lowe (below) controlled the ball with his left foot before tapping it on again and diving for the score in the corner.
Ulster, who had lost Jacob Stockdale following a collision with Moore, caught Leinster napping a few minutes later after a lineout in the corner and Cooney spotted McCann unmarked on the wing, and the in-form flanker dotted down for a well-deserved try.
Ulster looked tired and with Addison receiving attention, McCarthy cleaned up Moore's knock-on and Doris, James Ryan and Henshaw all had a hand in getting the ball to Larmour (above), who sprinted in at the corner.
Moore grabbed a fine try from the next passage of play, the full-back collecting Ethan McIlroy's chip ahead to win the race and put some gloss on the scoreboard.
Leinster stayed calm, however, and Van der Flier got in the end of the next attack to kill the game with 13 minutes left.
Lowry showed a clean pair of heels to score in the corner with the final play of the game as Ulster's season came to an end, while Leinster will travel south with their eyes set on a first final appearance in three seasons.
Leinster: Jimmy O'Brien; Jordan Larmour, Robbie Henshaw, Jamie Osborne, James Lowe; Ross Byrne, Jamison Gibson-Park; Andrew Porter, Dan Sheehan, Tadhg Furlong; Joe McCarthy, James Ryan (capt); Ryan Baird, Josh van der Flier, Caelan Doris.
Replacements: Rónan Kelleher, Cian Healy, Michael Ala'alatoa, Ross Molony, Max Deegan, Luke McGrath, Sam Prendergast, Ciarán Frawley.
Ulster: Stewart Moore; Mike Lowry, Will Addison, Stuart McCloskey, Jacob Stockdale; Billy Burns, John Cooney; Eric O’Sullivan, Rob Herring (capt), Tom O’Toole; Harry Sheridan, Cormac Izuchukwu, Matty Rea, David McCann, Nick Timoney.
Replacements: Tom Stewart, Andy Warwick, Scott Wilson, Greg Jones, Dave Ewers, Nathan Doak, Ethan McIlroy, Jude Postlethwaite.
Referee: Andy Brace (IRFU)
Watch highlights of all the weekend's URC action on Against the Head, RTÉ2 and RTÉ Player, Monday 7pm
