Madigan's boot gave the home side a slender and slightly fortuitous 9-6 half-time lead - after captain Jamie Heaslip was forced off injured - before a quickly taken tap-and-go try just after the interval gave his side some breathing room with Dan Tuohy in the sin-bin.

Ulter responded through Wiehahn Herbst but Jack Conan then crashed over in the dying moments of the game to round off a deserved win, leaving Ulster without a win in five against their Irish rivals and still with only one victory on the road this season in the GUINNESS PRO12.

Leinster were dealt a blow before the game even started with Shane Jennings ruled out late, and Jordi Murphy coming into the back row to replace him.

The atmosphere at the RDS was electric in a frantic start to the game, with both sides putting in huge hits and looking for early territory.

Ulster began the brighter side, playing a flat back line and putting on the pressure, before a Tuohy break on eight minutes from the 22 set up a deep drive into Leinster territory.

Ulster built the phases but a massive hit from Richardt Strauss allowed the hosts to turn the ball over and clear.

But they did not have to wait long to get the first points of the game, Pienaar testing his recovered knee ligaments with a sweetly struck long-range kick on 15 minutes after a high tackle, having seen a slightly longer effort come back off the bar two minutes before.

Leinster responded with a penalty of their own four minutes later, Madigan converting the simple kick after Ulster were penalised for not releasing after Luke Fitzgerald did well to recover a loose ball and drive for the line.

The visitors continued to put the pressure on at the breakdown, winning another penalty which Pienaar slotted to take the lead on 25 minutes when Leinster were guilty of not rolling away.

And things immediately went from bad to worse for the hosts as their skipper and talisman Heaslip was forced off with shoulder problem, leaving an inexperienced back-row with Josh Van Der Flier on.

But against the run of play two more Madigan penalties gave them a fortunate 9-6 half-time lead, Ulster guilty of repeatedly flying in off their feet, with Tuohy seeing yellow with just a minute left before the interval.

Ulster had to play the first ten minutes of the second-half with 14 men, and the Leinstermen took full advantage scoring the first try of the contest on 43 minutes.

Madigan fooled everyone in the RDS, as he feigned to kick a deep penalty into the corner before taking a quick tap and go and burrowing over the line, adding the extras superbly.

Ulster's heads did not drop however and tighthead prop Herbst drove over in the corner to bring his side roaring back into the game as the time ticked out on Tuohy's sin-bin.

Pienaar failed to add the extras from the touchline, leaving the score at 16-11, before Madigan took his and Leinster's tally to 19 points with another simple penalty on 58 minutes when Ulster were offside at the breakdown after a huge Leinster drive.

Ulster were immediately handed a needless chance to stay in the game, winning a penalty from the restart, but Pienaar's kicking boots were misfiring again as his poor effort missed by miles.

Leinster kept the ball and ferociously defended their lead for the last quarter of the game, Ulster not able to make any meaningful threats on the hosts try-line.

The hosts thought they had scored a late try to round off the win when Jimmy Gopperth looked to have hacked the ball over the line before touching down, but the score was ruled out by the TMO for a knock-on.

But man of the match Conan crashed over at the death after being fed by Devin Toner following Sean Cronin's powerful carry into the corner.

Madigan missed his first kick of the day with the conversion from the touchline, but it made no difference as Leinster ran out deserved winners.

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