Tries from Lions duo Jack Conan and Robbie Henshaw did the damage for Leinster in a hard-earned 21-17 win over Ulster at the RDS Arena.
Following Munster's defeat to Connacht, Leinster are now right back in the hunt for a place in next month’s north-versus-south Guinness Pro14 Rainbow Cup final.
An intense first half finished at seven points apiece, Cian Healy cancelling out Robert Baloucoune’s opening try with both defences thoroughly tested throughout.
Following a Billy Burns penalty, the hosts kicked it up a gear with replacement Conan and player of the match Henshaw both crossing before Craig Gilroy’s late score.
Ulster misfired in threatening positions early on, twice having line-outs stolen by James Ryan, and scrum-half David Shanahan was also stopped short of the line.
When the visitors pressed again in the 18th minute, they made it count. Jacob Stockdale expertly evaded a tackle from Dave Kearney and released winger Baloucoune for the right corner.
Burns, who added a fine conversion, was soon charged down by Ross Byrne, allowing Leinster to go close through Sean Cronin.
A quick bout of pressure in the 22 ended with Healy driving in under the posts for Garry Ringrose to convert.
Another missed chance for Ulster – this time from a maul – was preceded by an unsuccessful captain's challenge from Iain Henderson, with referee Mike Adamson deeming there was no contact to the head in Henshaw’s big tackle on Baloucoune.
Ulster were unable to profit from a James Hume break, and while the returning Caelan Doris replied with a turnover penalty, Ulster held out just before the interval thanks to a key rip by Stockdale.
Burns followed up a missed penalty with a successful 51st-minute strike, rewarding another strong run by number eight Nick Timoney.
However, Leinster then began to put together some relentless passages of attacking play. Conan hit the line at pace, exploiting a defensive gap to charge over from outside the Ulster 22. Ringrose converted again.
With their strong bench wielding influence, the reigning Guinness PRO14 champions enjoyed further gain-line success past the hour mark, leading to Henshaw muscling over from close range.
Showing his place-kicking prowess, Ringrose rifled over a classy conversion from wide out, yet the bonus-point try eluded Leinster.
A gallant Ulster closed out the scoring courtesy of replacement Ian Madigan’s long cut-out pass for Gilroy in the last minute.
It sparked some late drama but there were no further chances.