St Mary's College had the match wrapped up in the first 28 minutes, scoring three converted tries, then spent the next 52 minutes trying not to lose it. The home dressing-room was a sombre place in the aftermath of Saturday's game, the traditional rendition of Dublin In The Rare 'Ol Times, self-consciously muted as the players mulled over a disjointed display.

Coach Brent Pope said the overwhelming feeling amongst the players was one of annoyance. "There is no real elation in there and that's a good thing. They are annoyed at the way they played. We made a lot of mistakes, tried to over-complicate things and I suppose tried to play the same way that they did against Con last week.

"The conditions didn't allow for that. We should have had a fourth try by half-time, never mind over the 80 minutes. That's the third occasion we have squandered that bonus point this season. I'm happy to win and we still have an opportunity to make the playoffs."

Pope went on the pay tribute to Shannon's young players; they may have lacked the wherewithal to break down the St Mary's defence but they were wonderfully obdurate in refusing to accept defeat. Three defeats in a week may have tempered Shannon's aspirations this season - they're not giving up hopes of making the play-offs but the management does boast a pragmatic outlook - but Saturday offered further confirmation that they harbour a fine squad of talented young players. Shorn of their five internationals, Shannon looked to their senior players and in second row John Langford they were rewarded with a significant response. He just shaded the lineout duel with Malcolm O'Kelly, pinching enough opposition ball to deny St Mary's a reliable source of possession. The return of Shannon hooker Frankie Roche made a huge difference after the midweek lineout shambles.

If Langford inspired by deed then the gauntlet was taken up by several others, notably second row partner Brian Buckley, who had a storming game around the pitch, David Quinlan and Colm McMahon and behind the scrum, young centre John Davis, who continues to blossom. He was an immovable object in midfield.

Shannon's problems were twofold, in that St Mary's defended solidly and they lacked penetration behind the scrum. The backline jousting degenerated into a collision of midfields. Andrew Thompson's four penalties were all they could, and looked likely to, muster. Manager Niall O'Shea was justifiably proud. "I thought it was a fantastic performance from the young players, the best of the season. Things are a little out of our hands now, we need a few games to go our way. The lads are devastated but the character they have shown with three games in seven days augurs well."

The old reliables surfaced to guarantee St Mary's success. Victor Costello made the hard yards, Trevor Brennan the big tackles and Malcolm O'Kelly thrived in the loose. Denis Hickie grasped his only opportunity and Shane Jennings demonstrated his capacity to learn, albeit receiving a lesson in the basics of the position from the excellent McMahon.

The three tries were all products of good forward work. David Griffin made a fine break inside his own 22 before offloading to Hickie, who raced the last 50 metres.

Prop David Clare - he had a fine game - profited from an O'Kelly catch at a five-metre lineout to bustle past some inept tackling and Costello's short journey to the line from a five-metre scrum wasn't unduly delayed by would be tacklers. Mark McHugh kicked three conversions. Unfortunately for the home side the fourth try never arrived, not did it look likely to; St Mary's were guilty of poor decision-making, careless handling and over-complication in midfield.

SCORING SEQUENCE: 13 mins: Hickie try, McHugh con, 7-0; 17 mins: Clare try, McHugh con, 14-0; 28 mins: Costello try, McHugh con, 21-0; 42 mins: Thompson pen, 21-3. Half-time: 21-3. 45 mins: Thompson pen, 21-6; 60 mins: Thompson pen, 21-9; 70 mins: Thompson pen, 21-12.

ST MARY'S: P McKenna; D Hickie, G Gannon, M McHugh, J McWeeney; E Hekenui, E McCormack; P Tucker, P Smyth, D Clare; D Griffin, M O'Kelly; T Brennan, V Costello, S Jennings. Replacements: A Conboy for Gannon 9 mins; F Fitzgerald for Griffin 54 mins.

SHANNON: J Lacey; J O'Neill, A Thompson (capt), J Davis, M Lawlor; D Delaney, C O'Loughlin; M Horan, F Roche, D Costello; B Buckley, J Langford; R Collins, D Quinlan, C McMahon.

Referee: B Smith (IRFU).