The gigantic rugby ball that smashed through the ramparts of Cardiff Castle was a portent of things to come.
This town is about to get hit with the mother of all rugby parties. You can do two things: kick on and enjoy it, or duck for cover.
A heady mix of Irish, Welsh, Canadian and even Uruguayan fans are converging, preparing to turn the Millennium Stadium into a melting pot of sport and song. The rare carnival and pageantry of a World Cup weekend added to the atmosphere, as thousands of green-shirted fans disembarked from planes, boats, trains and camper vans and poured into the city.
The Scullion family from Belfast were admiring the giant rugby ball (actually an art installation) with Alanna (5) and Shea (10) delighted to be on tour with their parents.
Nearby, Therese Coffey (25) from Limerick was feeling smug as she's managed to avoid paying through the nose for accommodation. Her sister Maura (19) is studying in Cardiff and a ready couch was available. "I'm studying physiotherapy - hopefully I'll be with the team in a few years," said Maura, adding with equal confidence: "And we're going to win tomorrow."
But not everyone was so fortunate. "We are students so we can only afford to come to one match," said Ciara Keenan (22) from Gortletteragh, Co Leitrim, who was sat outside the Owain Glyndwr pub with Adrian Keaveney (21) from Leitrim town. "This weekend is it for us. Unless we reach the final, of course. We'd get the money together then, yeah."
Ruth Colgan (24) from Castleknock, Dublin, and Beth Bergin from Johnstownbridge, Co Kildare, had pushed the boat out, with their Cardiff trip stretching from Thursday to Monday. "We've mostly been shopping. And some drinking," said Ruth.
They were perched outside O'Neills, under the shadow of giant flags of all the rugby nations that flapped in a damp breeze above St Mary Street. But inside, the Irish bar was abuzz with a tide of green hats and blaring trad music. It was 5pm and the weekend had definitely begun, even if the World Cup was a few hours away.
Earlier, in Dublin Airport, fans had faced some delays. But the mood was optimistic, buoyed by beer and brass music from a swinging ensemble that veered wildly in repertoire from 'No Diggity' to 'Ireland's Call'.
Killing time at the bar were Keith O'Flynn from Tipperary and his colleague Brian Boutilier, from Nova Scotia. "As soon as I saw we were in the same pool as Canada I knew I had to get Brian over for the match," said Keith.
They both work for a gold-mining firm in Co Tyrone - but Brian didn't have glimmering hopes for his team. While proudly draped in a Canadian flag, he was not too proud to admit: "I'll just be happy if we get to score the first try." However he added: "When Irish people put on skates and beat us at ice hockey, then I'll sit up and listen."
Late into the evening, crowds poured into the special fanzone set up in the historic Arms Park, featuring giant screens, games and music. "We can hold 8,000 to 10,000 people and we would like to welcome everyone down," said production manager Kirsty Evans.
"We are right next to the Millennium Stadium so if you don't have a ticket, you will feel the atmosphere. You can still hear the crowd roar."
It was a meeting point for Rebecca (20) and Abigail Taylor (18), sisters and students in London and Sterling, Scotland, but enjoying a family reunion. "It cost as much as a fortnight in Tenerife," they admitted, but Rebecca had a plan to recoup her costs. "I have a tenner on Ireland reaching the final against New Zealand. Although I'd be worried they'd lose that game."