Man-of-the-match Rocky Elsom also helped himselt to a try as Magners League champions Leinster showed the greater composure when it mattered as they mustered their first inteprovincial win of the season.

After defeats at home to Munster and away in Connacht, Michael Cheika's men were determined that they would not fall to Ulster.

But the home side, thanks to a well-worked try from centre Darren Cave, were 7-3 leaders at half-time.

And alhough Elsom sniped over for a try just three minutes into the second half, Ulster made a real fight of it with a penalty brace from Ian Humphreys leaving the game tantalisingly poised at 13-13.

That was how it stood with just a quarter-of-an-hour remaining and just when it mattered, Leinster struck for Simon Keogh's decisive try.

In chilly conditions, Ulster full-back Bryn Cunningham won his 100th Magners League cap and home coach Matt Williams also welcomed back in-form winger Timoci Nagusa from a spell on the sidelines.

Trevor Hogan and long term absentee Gordon D'Arcy, who injured his forearm against Italy in last season's Six Nations, forced their way into the Leinster team.

D'Arcy started on the right wing, with Felipe Contepomi partnering Luke Fitzgerald at centre due to the absence of Ireland captain Brian O'Driscoll.

The fit-again Isa Nacewa slotted in at out-half and showed some nice touches alongside stand-in captain Chris Whitaker.

The game took a while to come to life as both sides opted to kick long and play territory in the opening exchanges.

A thumping hit by Elsom on Robbie Diack drew roars of approval from the visiting fans shortly after Contepomi had opened the scoring with an eighth minute penalty.

Leinster's forwards were beginning to gain ground, supporting each other well in contact situations, and Contepomi failed to follow up on their good work when he missed his second penalty opportunity on the quarter-hour.

Then Ulster sprung a counter attack which had the Ravenhill regulars on their feet. Girvan Dempsey failed to gather a high ball and Stephen Ferris hacked it on towards the Leinster try-line, launching a spirited chase.

Elsom got to the ball first but play was called back anyway by referee George Clancy and Leinster survived, only for the classy Cave to saunter over just a few minutes later.

Ulster hit the front in the 23rd minute when Leinster's rearguard was caught out by an Andrew Trimble decoy run and some good work by Isaac Boss, Ian Humphreys and Paddy Wallace.

The space was created for Wallace to send the fast-breaking Cave nipping past a flat-footed Dempsey and the Ireland 'A' international gleefully glided through to touch down to the left of the posts.

Humphreys added the conversion but Leinster ended the first half on the attack and were left frustrated when a couple of visits to the home 22 saw them return pointless and Contepomi also missed a second penalty.

Despite those setbacks, Leinster seemed a renewed force on the restart and Dempsey was held up over the try-line after a series of passes, which saw Nacewa feature prominently.

They remained on the front foot and Australian flanker Elsom was soon over for his try. Play was swung out to the left where Leinster had numbers and Elsom's score, which saw him muscle over from close range, was well converted from wide out by Contepomi.

Humphreys missed an immediate chance to reply but he was right on target with a 53rd minute kick to draw the sides level at 10-10.

Some indiscipline at ruck situations, a real failing of Ulster's earlier in the season, cost them again when Contepomi kicked Leinster back into the lead.

But a superb line-break from the bustling Ferris brought Ulster right back within scoring range.

D'Arcy got across to haul the flanker down, yet a subsequent penalty was awarded and Humphreys made no mistake from in front of the posts.

Over the remainder of the game though, Leinster snaffled back control and showed some admirable continuity as their forwards strung together the phases. Youngsters Devin Toner and Sean O'Brien impressed once again.

Although they endured some nervy spells, they kicked intelligently and were able to hold onto the ball for longer periods than Ulster.

And with elusive backs of the quality of Fitzgerald, D'Arcy and replacement Keogh, Cheika's side began to find holes in the home defence.

A poorly-judged chip and chase attack from Ulster's Wallace was returned with interest by the champions as Fitzgerald secured possession and D'Arcy broke into space, puncturing the defensive line with a surging run.

A floated 71st-minute pass out to the right from Contepomi was just the ticket for Keogh to dive over and score in the right corner, with only replacement Thomas Anderson close-by.

Contepomi failed to add the extras but he landed a penalty, five minutes later, as Ulster began to look increasingly desperate with time not on their side.

They carved out a final kick at goal for Humphreys, who was charged with trying to rescue a losing bonus point for his side, but his attempt from a fair way out fell short of the posts.