CLONTARF 14 GARRYOWEN 13, Castle Avenue
Scorers: Clontarf: Tries: Paul O'Donohoe, Niall O'Brien; Cons: Daragh O'Shea 2
Garryowen: Try: Willie Staunton; Con: Conor Kilroy; Pen: Conor Kilroy; Drop: Willie Staunton
Clontarf v Garryowen - Match Photo Gallery
In difficult conditions, Garryowen built up an early 13-0 lead. Conor Kilroy landed a penalty before Willie Staunton kicked a drop goal and the number 10 them cut through for a seven-pointer.
But two quick tries earned 'Tarf a half-time advantage.
Paul O'Donohoe scampered over and then Niall O'Brien linked with Daragh O'Shea for the second. O'Shea converted both and the hosts held on to take the spoils.
Coached by Andy Wood and Simon Broughton, Clontarf were beaten by Ballymena in a friendly last weekend and struggled initially to find their feet against their Limerick opponents.
After last season's semi-final disappointment, Garryowen looked determined to claim a first day win and with their forwards establishing an early foothold in 'Tarf territory, full-back Kilroy and out-half Staunton displayed their class.
The 'twin' threats of Conor and Ciaran O'Boyle were also getting their fair share of ball and 'Tarf looked under pressure.
The next score would be crucial and thankfully for the game's competitiveness, it fell to Clontarf.
Big back rower Heinrich Stride gained good yardage before he teed up O'Donohoe, the former Ireland Under-20 international, for a short, sniping run to the line.
The O'Boyles came across to cut off the scrum half's path but he muscled his way over, and with O'Shea converting, the hosts were right back in the game.
Ten minutes later, the Garryowen defence was sliced open again when a couple of dummy runs allowed the overlapping O'Shea enough time and space to put winger O'Brien hurtling over the whitewash.
O'Shea's conversion bumped 'Tarf ahead at 14-13 and with play cramped between the 22-metre lines during an attritional second half, Wood's men held on to their slim advantage.
Garryowen did have their spells of dominance but 'Tarf's tackling was resolute and they gritted their teeth to notch only their sixth win in 13 AIB League meetings with the Sky Blues.