Table toppers Lansdowne and defending champions Clontarf were the winners of two closely-fought Ulster Bank League Division 1A semi-finals today, as the pair set up an all-Dublin decider on Saturday, 9 May.

That game will take place on the main pitch at the Aviva Stadium, the scene of Lansdowne's epic 23-19 extra-time victory over Young Munster where a last-gasp try from hooker Tyrone Moran proved all-important for Mike Ruddock's men.

It was a heartbreaking finish for Munsters who came into the play-offs as 10/1 outsiders for the league title, but they coped well with two first half yellow cards and Gearoid Lyons' reliable boot had them within touching distance of the final both in normal time and extra-time.

Former Munster player Scott Deasy booted Lansdowne in front from an early scrum penalty, however his radar was off on a couple of occasions as the hosts failed to take advantage of the Cookies' high penalty count.

Young Munster centre Lyons equalised with his first successful kick on 25 minutes, the slippery conditions playing their part as attacks at both ends were foiled. The pressure increased on the visitors when they had two players carded in quick succession.

After Diarmaid Dee saw yellow for going off his feet at a ruck, Deasy briefly restored Lansdowne's three-point advantage before his opposite number Willie Staunton replied with a well-struck drop goal.

Lansdowne did manage to go in at the break with a 13-6 lead thanks to a well-worked converted try from centre Tom Daly. It owed much to a brilliant break from Leinster prospect Cian Kelleher, and supporting winger Ian Fitzpatrick did well to feed Daly with the scoring pass.

Munsters bounced back from that setback with an equally brilliant seven-pointer early in the second period. Right winger Diarmaid McCarthy, who threatened on a number of occasions, darted onto a Staunton grubber kick and beat the covering defender with Lyons converting.

Lyons delighted the travelling support by adding a pinpoint penalty from near the touchline, moving John Staunton's side ahead for the first time in what was developing into a very cagey affair. Lansdowne then turned the screw in the scrum once more, winning a penalty which young replacement Conor McKeon converted to make it 16-all and send the semi-final to extra-time.

It was first blood in extra-time to Munsters as a Lyons' penalty went over off a post, rewarding scrum half Rob Guerin for a fine initial break and good support work from replacement Kolio Hifo. Now 19-16 down, Lansdowne missed a chance to respond when McKeon was off target with a drop goal.

However, Ruddock's charges found the answers when it mattered most as they wore down a Munsters defence that was missing the sin-binned Craig O'Hanlon. Moran emerged as the match winner in the very final play, using his strength to power over just to the left of the posts. McKeon converted and with that, Lansdowne's players and supporters erupted in celebration.

Next month's final will see the last two Division 1A champions face off as Lansdowne attempt to lift the trophy for the second time in three years, while Clontarf will be looking to make it back-to-back triumphs.

Three penalty goals from Matt D'Arcy steered 'Tarf to a gritty 9-0 semi-final success at Terenure College as they bounced back from last week's Bateman Cup final disappointment in Cork.

The adverse weather conditions made it difficult for both sides at Lakelands and in the absence of injured out-half David Joyce (shoulder), inside centre D’Arcy assumed the place-kicking duties.

D'Arcy, Ireland's Club international captain this year, missed his first two shots at the posts and Terenure began to make inroads as their back-three of Ian Hanly, James O’Donoghue and Harry Moore handled more ball out wide.

Yet, despite the best efforts of Terenure out-half James Thornton, who was short with an 18th minute penalty, and Clontarf's Evan Ryan, who cut through midfield on a notable break in the closing stages, the teams played out a scoreless first half.

Thornton was agonisingly close to breaking the deadlock on the resumption, and another chance was lost when James Blaney's men failed to retain possession following an incisive back-line move.

It was D'Arcy who finally opened the scoring with a well-struck 51st-minute penalty. He failed to convert a subsequent effort and 'Nure's powerful lock Fergal Walsh was held up on a drive for the visitors' try-line, just past the hour mark.

Inside the final quarter hour, Thornton dragged a left-sided penalty to the right and wide and Terenure's frustration grew as D'Arcy split the posts at the other end with 71 minutes gone.

The hopes of last year's Division 1B winners took a real hit with yellow cards for lock Kevin O'Dwyer and scrum half Kevin O'Neill in the closing stages. Indeed, O'Neill went close to scoring a try before his exit from the pitch.

O’Dwyer did return to the 'Nure pack for the conclusion of the contest, but thanks to a routine D'Arcy penalty deep into injury-time, Clontarf's back-to-back title ambitions remain alive.

Meanwhile, Garryowen earned promotion straight back to the top flight with a hard-fought 13-3 play-off win away to St Mary's College. The visitors broke free from a defensive scrum in the first half, taking advantage of poor tackling as scrum half Neil Cronin ran in the game's only try.

Johnny Williams' hat-trick of tries propelled Dundalk to a memorable 22-10 play-off triumph over hosts DLSP at a wet Kirwan Park, as they booked their place in the new ten-team Division 2C for 2015/16.

In another historic first for Dundalk, Ene Fa'atau's side will be playing senior rugby in the Ulster Bank League next season. Their promotion caps off an incredible campaign for the Mill Road men who had already won the Ulster Bank All-Ireland Junior Cup, Leinster League Division 1A and the McGowan Cup in recent months.

Division 1A semi-finals:

Lansdowne 23 Young Munster 19
Terenure College 0 Clontarf 9

Division 1A promotion/relegation play-off:

St Mary's College 3 Garryowen 13

Division 2B Promotion/Relegation play-off:

De La Salle Palmerston 10 Dundalk 22, Kirwan Park