Leinster march on to yet another Champions Cup quarter-final after out-manoeuvring Ulster in the teeming rain at the Aviva Stadium.
Leo Cullen's men dealt with the brutal conditions better to set up a last eight clash with Leicester Tigers at the same venue next weekend - possibly on Good Friday - and with their sights still set on a fifth title triumph.
Before this fixture, the sides had met on 11 occasions since their close quarter-final encounter that went Leinster's way four years ago.
Since then, Ulster had only finished on the winning side on three occasions - but two of those wins came last season.
And, with Leinster missing Grand Slam heroes Johnny Sexton, Caelan Doris and Garry Ringrose, the in-form visitors fancied their chances.
Ultimately, however, it was another regret-filled evening for Dan McFarland's men as their long wait to bridge the gap to their 1999 success in this competition goes on.
For Leinster, it is the 18th time they have made it to this stage and Cullen will demand more with bigger tests still ahead.
Ulster were initially under pressure after Michael Lowry failed to hold Ross Byrne's kick-off but otherwise they had the upper hand in the opening stages as their rivals made a series of errors.
Andrew Porter was penalised for obstruction off Leinster's lineout in Ulster's 22, then Jordan Larmour's push on Nathan Doak into Jacob Stockdale earned the visitors another penalty.
Hugo Keenan's knock on in his own 22 as he tried to gather Doak's deflected grubber added to Leinster's problems.
And, after big carries from Nick Timoney and Kieran Treadwell, Doak clipped over a penalty from close range as the Blues infringed at the ruck.
It was the first time in this season's competition that Leinster had fallen behind but that stat only lasted for 90 seconds.
Ulster went off their feet from the restart and Byrne took advantage to restore parity with a penalty from 20 metres.
The Blues took the lead in the 20th minute with the first try of the evening.
Byrne kicked a penalty to the corner and while the lineout drive went nowhere, James Ryan kept the move alive and, off a mini-ruck, Ryan Baird crashed over the try line with help from Tadhg Furlong, with Byrne adding the extras for a 10-3 lead.
But Ulster hit back with a superb try of their own.
Having made one great take in the air, Jacob Stockdale launched a kick between Leinster's lines and gathered.
Then Billy Burns was alert to having men over on the right flank and he kicked to James Hume, who cut inside James Lowe to score.
Doak missed the conversion but it was game on, although the concession sparked the hosts back to life and Jack Conan thought he had scored Leinster's try in the 35th minute but the officials ruled that O'Connor stopped him just short of the line.
It took a series of big defensive efforts by Ulster to keep the damage to three points and a 16-8 half-time deficit, with Byrne eventually firing over a penalty as the visitors' line held.
A big Baird turnover, followed by his second row partner Ryan's important lineout steal in his own 22 off Rob Herring's throw, set the tone for the second half.
Then Gibson-Park came to prominence.
The scrum-half stepped it up with his tackle on Duane Vermuelen at the base of the scrum before blocking down John Cooney's first kick after coming on for Doak.
Ulster were buckling under pressure and a yellow card for James Hume followed before Leinster cruised clear.
Once again, the Blues went to their forwards to try to crack Ulster's defensive wall and, once more, were getting nowhere until Gibson-Park found Henshaw, whose pass to Byrne didn't go to hand.
But Gibson-Park retrieved it, squirmed out of Stockdale's tackle and away from McCloskey to score, and Byrne's conversion made it 23-8.
Back came Ulster with real intent and, with Dan Sheehan pinged for coming in a the side of the ruck, the visitors went to the corner.
This time Herring got their lineout maul working perfectly and, with his last act before he was replaced, the hooker stretched successfully for the five-pointer.
Cooney nailed the tough conversion and it was an eight point game again with 22 minutes remaining.
Yet again, however, Leinster turned the screw. O'Brien was the latest player held up - 21-year-old back row replacement Harry Sheridan did well to get under him to deny the score.
But the Blues made a five metre penalty count with Porter, with a little help from Furlong, muscling over and Byrne's conversion pushed Leinster well out of sight - even before Sheridan was sin-binned in the 68th minute.
LEINSTER: Keenan, Larmour, O'Brien, Henshaw (Frawley 73), Lowe, R Byrne (H Byrne 73), Gibson-Park (McGrath 67); Porter (Healy 70), Sheehan (McKee 70), Furlong (Al'alatoa 65), Molony, Ryan (Jenkins 68), Baird, van der Flier (Penny 55), Conan.
ULSTER: Lowry, Baloucoune, Hume, McCloskey, Stockdale, Burns (Moore 55)), Doak (Cooney 51); Sutherland (O'Sullivan 62), Herring (Stewart 59), O’Toole (Toomaga-Allen ht), O’Connor, Treadwell (Rea 67), McCann (Sheridan 47), Timoney, Vermeulen.
READ NEXT:
Dara O'Shea's season is over, Jayson Molumby set for month on sidelines
Brighton 'lucky' to have Evan Ferguson as big clubs circle Irish teenager
Keith Long on 'revisionism' at Dalymount Park over his Bohs reign
How Katie Taylor ticket prices compare to Michael Conlan's fight
Get the latest sports headlines straight to your inbox by signing up for free email alerts
