Leinster came through a nail-biting European Champions Cup rematch with Harlequins as Ian Madigan's 71st-minute penalty gave them a 14-13 win at the Aviva Stadium.
Matt O'Connor's men avenged last Sunday's 24-18 loss at the Stoop - but only just - as Harlequins had them on the ropes, particularly when scoring 13 points in 20 second-half minutes.
Isaac Boss' quick-witted try on the half hour, allied to two Madigan penalties, had Leinster leading 11-0 at half-time in Dublin. However, the dominant Quins scrum provided the platform to launch their comeback.
Tim Swiel, in for the injured Nick Evans at fly-half, found his kicking range with two penalties and an excellent conversion of Mike Brown's well-worked 56th-minute try.
The Londoners looked to have the winning of the game until replacement Eoin Reddan inspired the Leinster men by tapping two penalties.
The territory gained led to Madigan's crucial kick and the Blues survived a frenetic finish during which Quins lock Charlie Matthews was sin-binned three minutes from time.
The losing bonus point is enough to keep Conor O'Shea's side at the top of Pool 2, but Leinster are level with them on 13 points ahead of two fascinating final rounds next month.