There's a strange, almost inexplicable force at work in Irish club rugby. However much the storyline may vary, when there's a Limerick/Dublin match-up, the outcome usually ends up the same. It's a dog-eared script and it's gone beyond a cliche at this stage.

In any other match-up you wouldn't have given a prayer for Garryowen's chances nearing the halfway point on Saturday; 17 points down, a man down and being scrummaged off the park. Except that this was Garryowen in an AIL semi-final at home, and, of course, this was St Mary's College.

There had been a variation on this theme while Lansdowne were making hay as the sun shone before buckling to Buccaneers a week before, and countless variations on all the St Mary's losing trips to Dooradoyle since the AIL's inception - a year ago they snatched defeat from the jaws of victory by a point. But this took the biscuit.

Where St Mary's panicked and lost their way, Garryowen rolled up their sleeves and went for the jugular. A mighty 45-metre penalty on the half-time whistle by Killian Keane had reduced Garryowen's leeway to two scores, whereupon Keane gave his halftime address.

If the dismissed Kieran Ronan felt bad now, imagine how bad he was going to feel if Garryowen lost, said Keane. He pointed out that they now had nothing to lose and may as well give it an almighty lash. Then, out of the mouths of babes, 18-year-old outhalf Jeremy Staunton calmly chipped in to a slightly flabbergasted John Hall: "Don't worry, we'll win, we'll win."

Staunton himself didn't have a particularly good game. Part of the reason he's so endearing on the pitch is that when he gets it wrong, he gets it spectacularly wrong - a left-footed chip ahead didn't just clear the dead-ball line, it went into the trees.

But there was one incident which perhaps typified how he and his team-mates are weaned on that winning mentality. After Dennis Hickie fumbled his first high kick of the game just past the hour, when the ball next came Staunton's way you just knew it was going to be another garryowen at the St Mary's right winger. Sure enough, up it went into the clouds, the crowd roared and Hickie fumbled it again, giving the home side a five-metre scrum.

Garryowen just kept coming, tearing into every ruck with venom. With Ben Cronin sacrificed after Ronan's dismissal, the storming Paul Hogan made light of their numerical advantage in the back row, while behind them Tom Tierney kicked shrewdly, passed crisply and ran the show with a little help from Staunton and Keane.

Garryowen didn't particularly create much, St Mary's `scoring' the game's two tries and creating the bulk of the scoring chances. After a very debatable penalty try kept Garryowen in touch, St Mary's began to crack and three penalties in the last eight minutes of normal time by Keane steered them home. Somehow, you almost knew it would happen. It was so implausible it was inevitable.

"That's the Limerick factor I guess," said Hall, the Bath man with the wondrous look in his eye. Yes, he agreed, the sending-off of Ronan provided an immediate wake-up call for his charges.

Indeed, it wouldn't be stretching the point to say that Ronan's dismissal, bizarre as it sounds, was the turning point of the match, and without which Garryowen may not have won.

In a typically candid and honest assessment, his Limerick-born counterpart, Steve Hennessy, conceded: "We gave away too many silly penalties, we lost our shape, we lost our composure."

How St Mary's didn't make a dominant scrum and an extra man in the back row tell only they know. Only once did Conor McGuinness make a trademark, left-handed scoop break to the blind side. Costello stopped rumbling and Hickie, who had the beating of Kevin O'Riordan, was never used from such a scrum platform with an inviting blindside channel to the right.

Instead Costello played footsie to no obvious purpose save to run down the clock and from the resultant re-scrum, Costello did it again only for Trevor Brennan to break early and concede the second of those three late penalties. Talk about shooting yourself in the foot, and this with three current internationals in the middle five!

All of which provided shades of St Mary's tactical disintegration and lack of leadership in similar circumstances last year to Shannon in the semi-finals. "We blew it that day, but we really blew it today," admitted Hennessy. "We may never have a chance like that again."

Hennessy stressed that Dave McHugh "wasn't great, for either side." Untypically, McHugh missed knock-ons and forward passes, but most of all it was hard to dispute Hennessy's claim that "I felt there was an element of levelling things out as the game went on."

You see it in all team sports and, of course, referees are only human. Perhaps also part of the Limerick factor - the Dooradoyle crowd got onto McHugh's case continuously, after the sending-off especially, and were baying for the numbers to be evened out at the merest whiff of an incident.

For 10 minutes they were. Steve Jameson was sin-binned for, he claims, taking Garryowen's middle of the line jumper Shane Leahy out while he was jumping at two. "I didn't touch him and there was no warning. That was the longest 10 minutes of my life. Well, that's me finished now."

"IRFU rules" prevented McHugh from making any explanation for that, or the penalty try, awarded after a quick tap by Pat Humphreys 10 metres from the line which saw him hauled down two metres from the line. Apparently it was for diving in to kill the ball.

"The penalty try was very harsh," maintained Hennessy, besides which the penalty count was something like 11-1 after Ronan's dismissal. Where before his decisions seemed to have swayed towards St Mary's, then they went heavily Garryowen's way.

But the bottom line was that Garryowen dug deeper and played the winning rugby. As one former Garryowen international observed as the delighted light blues made for the dressingroom, and the dark blues departed just shaking their heads: "You can't beat balls when it comes down to it."

Scoring sequence: 7 mins: McWeeney try, Campion conversion, 0-7; 14: Campion penalty, 0-10; 31: McKenna try, Campion conversion, 017; 40: Keane penalty, 3-17; 60: penalty try, Keane conversion, 10-17; 72: Keane penalty, 13-17; 77: Keane penalty, 16-17; 79: Keane penalty, 19-17.

Garryowen: D Crotty; C Kilroy, K Hartigan, K Keane (capt), K O'Riordan; J Staunton, T Tierney; N Hartigan, P Humphreys, K Ronan, S Leahy, D Peters, P Hogan, B Cronin, D Wallace. Replacements: R Laffan for Cronin (39 mins).

St Mary's College: K Nowlan; D Hickie, P McKenna, R McIlreavy, J McWeeney; F Campion, C McGuinness (capt); J Maher, P Smyth, P Coyle, S Jameson, D Bourke, T Brennan, V Costello, M Cuddihy. Replacement: I Bloomer for Bourke (28 mins).

Referee: D McHugh (Munster).