Clontarf were crowned the inaugural All-Ireland T20 champions after a 10-run victory against Waringstown in a thrilling encounter at the Lawn.
Needing 18 runs from the final two overs, Waringstown managed just 7 as Man-of-the-Match John Mooney and Ropu Islam bowled superbly at the death.
Mooney (2-14) had earlier struck two decisive blows removing James Hall and Lee Nelson cheaply as the home side chased 152.
Adam Dennison struck five boundaries in his 34, but it was Irish international Greg Thompson who looked like being the match-winner as he unfurled his repertoire of cuts, pulls and reverse sweeps to score a rapid 50 from just 29 balls (4 fours, 3 sixes).
His dismissal by Andrew Poynter (2-20) swung the game back towards Clontarf, but Kyle McCallan's three consecutive boundaries off Islam in the 18th over set the contest back on an even keel before the nerveless Mooney took control of the penultimate over and Islam, as he had done in the Leinster decider showed his skill and calmness under pressure.
The Clontarf innings of 151 for 8 was founded around a 66-run stand for the fourth wicket between top scorer Waqar Azmat (36) and Mooney (28).
The foundation though was set by a blistering power-play as Bill Coghlan (21), Brad Barnes (17) and Andrew Poynter (25) were all among the runs as 56 came in that six-over period.
Earlier in the day, Waringstown reached the final with an emphatic 67-run win against Bready, totally outplaying their NW opponents.
Early wickets for Irosh Samarasooriya had the game in the balance at 41 for 3, but an early reprieve for James Hall was to prove costly as he and Greg Thompson took the game away from Bready.
The pair added 110 in 12 overs, with former Irish international Hall top scoring with an unbeaten 74 from just 52 balls, which saw him clear the ropes five times as well as hitting three fours.
Thompson also scored quickly, as his unbeaten 47 came from 37 balls - 6 fours and 1 sis - as Waringstown finished on 164 for 4.
The Bready reply never got going, with only David Rankin (22) and Andrew Austin (21) passing 20. They took Bready to 57 for 2, but the required rate at that stage was already well into double figures, and scoreboard pressure told as they lost six wickets for 31 runs, eventually finishing on 97 for 9.
In the other semi-final at Wallace Park in Lisburn, Clontarf emerged victorious, overcoming Cork County by 47 runs.
John Mooney top scored with 42 as Clontarf posted 134 for 8 - Robert Forrest chipping in with a valuable 24.
Cork County weren't able to break the shackles of the strong Clontarf attack, despite the best efforts of Gary King who top scored with 40 as they finished on 87-7 - Clontarf victors by 47 runs.
ALL-IRELAND T20 FINALS DAY
Final, At The Lawn, Clontarf beat Waringstown by 10 runs
Clontarf 151-8 (W Azmat 36, J Mooney 28, A Poynter 25, B Coghlan 21; K McCallan 2-22, G Kidd 2-24)
Waringstown 141-7 (G Thompson 50 , A Dennison 34, K McCallan 27*; J Mooney 2-14, A Poynter 2-20, J Morrissey 2-21)
Semi-Final 1, At Wallace Park, Clontarf beat Cork County by 47 runs
Clontarf 134-8 (J Mooney 42, R Forrest 24; S Joshi 2-27)
Cork County 87-7 (G King 40, T Clifford 20)
Semi-Final 2, At The Lawn, Waringstown beat Bready by 67 runs
Waringstown 164-4 (J Hall 74, G Thompson 47*; I Samarasooriya 4-23)
Bready 97-9 (D Rankin 22, A Austin 21; J Mitchell 3-17, L Nelson 2-9, K McCallan 2-32)