In a dour opening half Darragh Oâ00Shea gave Clontarf the lead with a penalty after eight minutes. Jeremy Manning was off target with two kickable penalties before being successful with his third attempt on thirty three minutes to leave the sides level 3-3 at the interval.
Clontarf took control in the second half with their man of the match Heinrich Stride going over for a try eight minutes into the half and Martin Dufficy converted.
Dufficy and Manning exchanged penalties before a great forward drive saw another try for Clontarf with Stride being credited with the touch down on seventy three minutes and Dufficy converted.
Substitute Max Rantz McDonald rounded off a great day for the Dublin side when he touched down for a third Clontarf try.
Scorers: Cork Constitution: J Manning 2 pens.
Clontarf: H Stride 2 tries, M Rantz McDonald try, M Dufficy 2 cons, 1 pen, D Oâ00Shea pen.
What a difference a year makes. Twelve months ago Garryowen went to Coonagh and whipped Shannon but yesterday at the same venue, and in atrocious conditions with a strong wind and heavy rain, Shannon overturned that result and qualified to face Clontarf at Thomond Park.
The bragging rights well and truly belong to the Shannon forwards after this latest episode in their many derby clashes and such was the power of the winners pack that Garryowen were restricted to only a few incursions in the entire second half.
Prop Kevin Griffin, hooker Mike Essex, lock Padraig Oâ00Brien and the entire backrow of Donnacha Ryan, Eoghan Grace and David Quinlan ensured that Shannon kept it tight and denied the speedy Garryowen backs the chance to show their paces.
Behind the scrum Frank McNamara had a splendid game at scrumhalf and Tadgh Bennett kicked well.
For Garryowen it was a bitter disappointment but it was certainly not the fault of fullback Conor Kilroy who had a superb game, apart from landing their twelve points with three penalties and a drop goal.
Paul Neville led by example in the pack with Declan Lavery and Ed Mackey also getting through an amount of solid work.
Garryowen were given the wind for the first half at the end of which they led 12-7.
Conor Kilroy landed a Garryowen penalty after only two minutes but then came Kellyâ00s try two minutes later which Bennett converted.
A penalty, drop goal and another penalty all by Kilroy gave Garryowen their interval lead but five minutes into the second half Bennett landed a penalty.
But the home side, at Coonagh, had to wait until ten minutes from the end to regain the lead when Bennett kicked a penalty from in front of the posts and he did so again five minutes from the end of what was a very keenly contested affair.
Stephen Kelly almost got in for a last second try for Shannon but it mattered little at that stage.
Scorers: Shannon: S Kelly try, T Bennett e pens, 1 con.
Garryowen: S Kilroy 3 pens, 1 drp gl.
Shannon: D Oâ00Donovan; R Mullane, F McLoughlin, J Clogan, S Kelly; T Bennett, F McNamara; K Oâ00Neill (L Hogan, 48 mins), M Essex, K Griffin; P Oâ00Brien, F Walshe; D Ryan, E Grace, D Quinlan.
Garryowen: C Kilroy; R Oâ00Mahoney, K Lewis, C Doyle, L Bourke; W Staunton(Andrew Bourke, 70 mins), G Hurley; R Brosnan, M Sherry, D Lavery; E Mackey, F McKenna (J Oâ00Sullivan, temp); P Neville, C Hartigan (J Oâ00Sullivan, 48 mins), D Sherry (Neville Melbourne, 62)
Referee: G Clancy (M.A.R.)
Defending champions U.C.C. are through to the Second Division final after their deserving victory over Old Crescent at the Mardyke.
The home side led 9-6 at half time with three penalties from Gavin Dunne to two by Brian Oâ00Shea.
College took over after the break and tries by Sam Cronin, Will Oâ00Donoghue and Colin Oâ00Brien saw them book a final place. Dunne converted two of the tries and also added a penalty. Aaron Carroll replied with a try for the Limerick side and Oâ00Shea converted.
Scorers U.C.C.: S Cronin, W Oâ00Donoghue, C Oâ00Brien tries, G Dunne 4 pens, 2 cons,
Old Crescent: A Carroll try, B Oâ00Shea 2 pens, 1 con.
Ballynahinch won promotion to the First Division with a 66-3 home win over Highfield at Ballymacarn Park. Conor Oâ00Leary kicked a penalty for the visitors in the opening half.
Promoted Corinthians defeated Midleton 29-14 in their semi final at Corinthian Park. Jeff Hitchmough scored two tries and also converted both for the East Cork side.
Corinthians will face Old Wesley in the final after the Dublin side defeated Queens University 38-25.
In a thrilling game at Musgrave Park Sundayâ00s Well retained their senior status with a 20-3 win over Cashel in the Third Division play off.
This was a typical Munster Cup tie and the scoreline does not do justice to the performance of the Tipperary side.
Playing with the strong wind in the opening half, the home side jumped into an early 10-0 lead with a penalty from Chris Burnett and a try by Dave Twohig which Burnett converted. A late surge just before half time saw Burnett extend his sideâ00s lead with a penalty and he than converted a second try by Twohig.
With the wind at their backs Cashel dominated proceedings in the second half but their decision to run several kickable penalties proved costly as the stubborn â00Well defence held firm. Cashelâ00s only score was a penalty by Pat Oâ00Connor.
AIB All Ireland League Division 1 Semi Finals:Cork Constitution 6,Clontarf 25;
Shannon 16,Garryowen 12;
Division 2 Semi Final:U.C.C. 31,Old Crescent 3;
Division 2:Ballynahinch 66,Highfield 3;
Division 3 Semi Finals:Corinthians 29,Midleton 14;
Old Wesley 38,Queens University 25;
AIB All Ireland League Division 3 Play Off:Sunday's Well 20,Cashel 3;