Nothing delights sport like an ambush. Yesterday the Leinster rugby team performed the mother of all ambushes. They were supposed to go gently into the night of defeat. Instead they dominated a pulsating game and graced a fine sporting occasion, defeating the high kings of Munster. Croke Park hadn't seen such divine inspiration since the Eucharistic Congress of 1932.

The final score was 25-6 but the smell of an ambush was in the air from the off. A world record crow of 82,208 witnessed this tale of the unexpected.

From start to finish a team that was expected to roll over before the Munster bandwagon played like demons. These were not the ladyboys of caricature. In the stands their supporters provided an ample soundtrack. Even more than the team the Leinster supporters have been the butt of a thousand jokes. They were regarded as a repository for all the social ills perpetrated by the doyons of Dublin 4 rugger down through the ages.

Yesterday they belied the predictions that their numbers had been decimated when they showed up, matching their fabled opponents in voice and colour. They performed their own ambush by defending from the stadium in the last hour before kick-off. Before that, it looked as if Munster were destined to dominate both on and off the pitch.

A similar story was written across the streets and warrens that lie in the shadow of Croke Park. Everywhere you looked, it was the red of Munster. If you didn't know better, you'd swear that they were the home team, an army of Dubs who had died and dyed their colours and returned speaking in funny accents.

The only place that Leinster was visible was on hoisted posters bearing the legend: "Believe in Leinster". The poster also bore the name of the team's sponsor, Bank of Ireland. Who in their right mind would put the words "bank" and "believe" on the same sheet of paper these days? Rumour had it that the core support was going to be bussed across the river from Donneybrook just before kick off, and dispatched back to safety soon after the final whistle.

Everybody else from the geographic entity appeared to be declaring for the opposition. This species, know as Lunsters, were easy to spot. They wore the predominant red, but when they spoke, it was in an accent borrowed from Ryle Nugent. They are unsound people, these Lunsters. They know not what they do.

Munster, for its part, is no longer a club or province, but a bandwagon. The Munster brand now stands for the capacity to bore the pants off anybody who doesn't themselves bore for Ireland about Munster.

Standing amidst the throbbing mass at the top of Jones Road before kick off was one Frank Quilter, a Kerryman who had commandeered a London taxi full of Seán Kellys. From early yesterday, Quilter began attaching his Kellys to lamp posts on approach roads to the stadium. The cardboard cutouts were not so much lifesize as larger than life, measuring a few inches taller than the man himself.

Kelly is a former president of the GAA, and was yesterday promoting his candidacy for election to the European Parliament in the South constituency. His man on the ground, Quilter, was fretting in the early part of the day that the candidate mightn't make it in time. Kelly was reportedly trying to negotiate the savage traffic clogging up the N7 from Limerick.

"The cardboard cutouts will do until he arrives," Quilter said, before glancing at his watch with the trepidation of one who has been stood up for a date.

"Loads of people want their photo taken with him. We're flying."

On the pitch, it was the southern/allegedly home provice which was flying. But yesterday was Leinster's hour in the sun. The ladyboy has been slain. The Munster bandwagon had shuddered to a stop.

What now for those poor, bedraggled displaced Lunsters?