Since the return of the play-offs in 2009-10, no team had won an away semi-final and Leinster - who finished the regular season atop the table - ensured that streak continued at the RDS Arena on Friday night.

The hosts were clinical in attack and immovable in defence as they maintained their record of having not been beaten at home in the Guinness PRO12 this season.

Ulster's chances of reaching the PRO12 grand final for just the second time were hanging by a thread after a first quarter completely dominated by the hosts as Isa Nacewa's early try and two Jonathan Sexton penalties saw them race into a 13-0 lead.

But the visitors finally got a foothold and a pair of Paddy Jackson three-pointers, as well as Craig Gilroy's try just before the break, narrowed the deficit to 13-11 at half-time.

However, Leinster again kicked on in the second half as man-of-the-match Jamie Heaslip and replacement front-rower Sean Cronin crossed the whitewash to seemingly put the game out of reach.

Gilroy's second try did give the visitors hope entering the final ten minutes but an impenetrable defence meant it was ultimately the home side who booked their place in the PRO12 final for the sixth time in seven years.

The result also means Ulster have never won a knock-out game, in any competition, against their Dublin-based rivals and the search for a first league title since 2005-6 goes on.

Just before kick-off, Leinster coach Leo Cullen said his troops were understandably feeling edgy yet they flew out of the traps like a team possessed and opened the scoring through Nacewa on four minutes.



Early pressure led to 14 phases of enterprising rugby before scrum-half Eoin Reddan fired a bullet of a miss-pass out to the captain on the right touchline and he cut inside one defender before lunging for the line with the TMO confirming he indeed grounded the ball.

Sexton slotted the conversion and got another chance to demonstrate his kicking boots on ten minutes as he nailed a 45-metre penalty after Chris Henry failed to roll away.

At that point Leinster had, incredibly, made 32 carries to Ulster's four and the blue swarm continued before another penalty soon after from Ireland fly-half Sexton made it 13-0.

Lesser teams than Ulster would have folded after the early onslaught but instead they slowly began to edge their way back into the match, forcing Reddan to gather a tricky bouncing ball behind his own try-line before they earned a 27th-minute penalty in front of the posts, which Jackson duly converted.

He made no mistake from close-range once again on the half-hour mark to close to 13-6 and two minutes before the break, they got the try their second-quarter fightback deserved.

After nine phases, the ball was spread wide to Gilroy who dived over in the corner despite Dave Kearney clinging on in an effort to push him into touch and the TMO confirmed he stayed in bounds to send the substantial contingent of travelling fans, inlduing golfer Rory McIlroy, into raptures.

It was the winger's fourth try against the Dublin-based side and brought Ulster back in with a chance of being the first away team since Newport Gwent Dragons in 2015 to win a Guinness PRO12 match at the RDS Arena.

Les Kiss' troops even started the second period with some territory but Leinster turned the screw once and for all - Heaslip demonstrating his considerable strength to barrel over the line on 48 minutes after Ben Te'o's sumptuous offload to the No.8.

The hosts continued to control the territory following that score and eventually broke Ulster down again on 64 minutes when replacement prop Cronin was fed the ball and powered his way over.

Sexton was again perfect from the tee as the regular-season table-toppers appeared to have killed the game off at 30-11 but Ulster proved their resilience by refusing to lie down.

Gilroy cut an unstoppable line coming in off the blindside wing from a scrum to scythe through for his second try of the evening and Jackson's conversion narrowed the deficit to 12.

That glimmer of hope with ten minutes remaining was soon extinguished however as Leinster refused to buckle defensively and can look forward to the final at BT Murrayfield next Saturday.