They have something that's intangible, indefinable and indescribable which, on days like this, makes them indestructible. Shannon have something you just can't bottle. It's why, unlike anyone else, they're never truly beaten until the fat lady sings.

So it was that when you looked at the stop watch and saw two minutes left as Mark McDermott prepared to throw to a four-man line-out on the Ballymena 22, you thought: Just enough time for them to do it.

That they did it entering the last minute of time and through a cooly-conceived try going left and away from their main strike runner, right-winger John Lacey, shows that they've more strings to their bow than perhaps ever before.

Try-scorer Billy O'Shea revealed that out-half Jim Galvin had "called the move five minutes before and no-one changed it". He only realised it was still on when Galvin skip passed to Andrew Thompson. The left-winger straightened the line and turned for centres Rhys Ellison and Paul McMahon to loop around him. McMahon did very well to get his pass away and according to the modest O'Shea himself all he did was "manage to get the ball and fall over the line".

O'Shea does himself a disservice, for he changed his angle of running superbly to complete an abysmal afternoon for the ever-vulnerable winger James Topping by taking him on the inside. The Shannon man then took the full force of Derek McAleese's covering tackle.

As events transpired, referee Murray Whyte had signalled that Ballymena had drifted offside in a desperate attempt to cut off a putative drop goal attempt by Galvin. But that wouldn't have left such a good after taste to an intriguing, flavoursome dish. Rightly, it also made the win all the sweeter for Shannon.

"The sweetest of the four years," reckoned Niall O'Donovan, the architect of the three-in-a-row of All-Ireland League wins who's now assisting coach Pat Murray. That verdict was a compliment both to Shannon's seemingly bottomless well of spirit as well as the heavyweight challenge presented by Ballymena - the best side to come out of Ulster in the AIB League's history and, according to all Shannon folk, the best side to come to Thomond Park in the last four years.

Shannon had to dig deep, in some ways deeper than they'd ever dug before. Captain and inspiration Anthony Foley, along with the multi-talented Eddie Halvey and evergreen prop Noel Healy had been unable to train all week.

Foley and Halvey, two of their key men, were particularly troubled; the former by a bruised sternum made worse by Stephen Ritchie's thumping 15th minute hit, and the latter by an ankle strain which left him limping perceptibly from early on.

Indeed, had only one of them been injured he would probably have gone off at half-time. When it was suggested Halvey should do so, Ellison pointed out that Foley was, er, "not 100 per cent" either.

So, Halvey disappeared briefly to the dressing-room and, according to O'Donovan, "we asked the guys at half-time to just give us what they could, and they produced a performance like that, which is outstanding as far as I'm concerned." It was no steal either. Helped by a subtle change in tactics, Shannon put Ballymena on the back foot. Foley, Halvey, Mick Galwey and Alan Quinlan were instructed to take the ball up the middle rather than out wide. Pop and go, pop and go; the biter was being bit.

With John Lacey (light years ahead of Topping in this regard) luring Derek McAleese to kick the ball down his throat by stealthily patrolling the line and Galvin generally out-kicking McAleese, Ballymena were limited to just two meaningful sorties outside of their half in the second period.

Halvey, brilliantly playing through the pain barrier, disrupted the Ballymena throw with that peerless ability to stay airborne; directing the lifters and scrum-half Gavin Russell like a tank commander. Apparently the Irish management don't like the way Shannon use him, but a greater presence at Shannon games and more communication could surely make more of a genuine talent.

Appropriately, it was Halvey who rose for the final catch, and Foley who stormed up the middle; the promising 19-year-old Marcus Horan taking it on for the O'Shea party piece. Cue the fat lady, or in this instance the heartiest dressing-room rendition of There Is An Isle this season.

For Nelie Smith, Ballymena's South African coach, and some of his players it had probably been a bit of an eye-opener. Against the champions, you're taking on more than 15 men; more even that a parish. The crowd, in truth probably not much more than 5,000, were still able to make the noise of thrice that. It helped carry Shannon home, and helps explain the four-year unbeaten home record.

Alluding to this, an almost envious Smith said: "To play with such support on your own ground and tremendous atmosphere must be quite an experience. That's why Shannon are a winning team."

Smith lamented the missed try-scoring opportunities, "from right at the beginning, through elementary mistakes, by not moving the ball from A to B and scoring". In particular, there was Jan Cunningham's looped pass behind the overlapping Park after two minutes, and a combination of Stanley McDowell's pass allied to Topping's positioning and handling which destroyed the chance of a break-out try when they were 109 ahead after 52 minutes.

Although Ballymena were deservedly rewarded for their imposing start their try was a dubious fluke - McAleese had run yards ahead of Dougan before the kick-ahead which bounced exaggeratedly for him and Michael Rainey to put McDowell over.

The aforementioned break-out apart, ignited by one of their trademark steals in physical contact by Gary Longwell, their second-half display was devoid of imagination. Their back play was often laboured and lacked the well-rehearsed variations of Shannon's midfield play with McDowell looking a long, long way away from Irish substitute material next week.

Unable to get their maul moving, and with McAleese not kicking them into position, they created little or nothing. The suspicion lurks that there's a hint of flat track bullies about them, or in their case mudheap bullies.

However, they have an immense physical strength throughout their team, along with pace out wide, and play it simply, even if they do lack subtlety or variation. "Ballymena came down here to do business today and in fairness to them they're a super side," said O'Donovan. "They did their homework well and it just took a very gutsy performance from our team to put them away."

Guts aplenty, along with skill and a coolness of nerve amid nerve-jangling tension. They just don't panic. It's why they're still the best.

Scoring sequence: 9 mins: Thompson pen, 3-0; 23: McDowell try, McAleese con, 3-7; 29: Thompson pen, 6-7; 33: McAleese pen, 6-10; 36: Thompson pen, 9-10; 71: Thompson pen, 12-10; 74: McAleese pen, 12-13; 79: O'Shea try, Thompson con, 19-13.

Shannon: B O'Shea; J Lacey, P McMahon, R Ellison, A Thompson; J Galvin, G Russell; M Horan, M McDermott, N Healy, M Galwey, J Hayes, A Quinlan, A Foley (capt), E Halvey. Replacements - K Keane for Healy (75 mins).

Ballymena: J Cunningham; J Topping, M Rainey, S McDowell, A Park; D McAleese, A Matchett; N McKernan, S Ritchie (capt), R Irwin, G Longwell, R West, A Graham, K Gallick, A Dougan. Replacements - D McCartney for Graham (73 mins).

Referee: M Whyte (ARLB).