Captain Garry Ringrose scored two second-half tries as Leinster recovered from Cian Healy’s early sending-off and a 19-point deficit to clinch a 38-29 bonus-point win over Ulster at the RDS.
Leo Cullen’s men trailed to tries from Rob Herring, Kieran Treadwell and Ethan McIlroy following Healy’s head-on-head tackle on Tom Stewart in the 20th minute.
However, with Ronan Kelleher reducing the deficit to 22-10 by half-time, the United Rugby Championship leaders roared to their ninth straight victory thanks to Ringrose's brace and scores from Andrew Porter and James Lowe.
It was a missed opportunity for Ulster, who had tasted victory here last year. They lost both James Hume and Nick Timoney to the sin bin but gained a late bonus point through replacement Sam Carter.
Ross Byrne’s second-minute penalty punished Stuart McCloskey for not rolling away before John Cooney levelled to reward Martin Moore for forcing a scrum penalty.
Knock-ons from Jamison Gibson-Park and Billy Burns summed up a stop-start opening quarter, yet the loss of Healy was immediately exploited by the visitors.
Stewart’s replacement Herring scored from a lineout drive in the left corner, Cooney nailing the difficult conversion for a 10-3 lead.
After Burns drew a high tackle from Byrne, McCloskey and Moore were stopped short before powerful lock Treadwell widened the margin to 14 points.
Leinster was stung further when Stewart Moore used turnover ball to race clear up the right and release McIlroy to canter to the posts.
Hooker Kelleher piled over from a late maul, with Byrne converting from out wide, and Leinster’s international-laden bench brought plenty of impact.
Ringrose nimbly spun away from Hume for a slick 58th-minute try, converted by Byrne. It was a double blow for Ulster, with Hume sin-binned for head contact.
Scorers:
Leinster: Tries: Ronan Kelleher, James Lowe, Garry Ringrose (2), Andrew Porter. Conversions: Ross Byrne (5). Penalty: Ross Byrne.
Ulster: Tries: Kieran Treadwell, Ethan Mcilroy, Rob Herring, Sam Carter, Nathan Doak. Conversions: John Cooney (2). Penalty: John Cooney.
