Cardiff (United Kingdom) (AFP) – Wales fans massing in Cardiff were trying — and failing — to keep a lid on their excitement in the build-up to the biggest football match in the country’s history on Wednesday.

As Wales prepared to take on Portugal in their 2016 European Championship semi-final in the French city of Lyon, some 27,000 supporters were heading to the Millennium Stadium in the Welsh capital to party and watch every second of the action on giant screens.

The stadium is considered the cathedral of the national sport of rugby union, but on Wednesday there was no doubt that football ruled the roost in Cardiff.

Plenty of people on the city streets were basking in the sunshine in Wales football shirts — in both home and away colours — while some girls were getting their faces painted with the Football Association of Wales coat of arms.

Draped in the Welsh flag, others were outside Cardiff Central railway station singing “Don’t Take Me Home”, the terrace chant that Wales fans have sung around France throughout Euro 2016.

Special souvenir half-and-half match scarves were being sold for £6 ($7.75, seven euros) in Cardiff city centre.

Others were selling ‘jester’ hats in the red, white and green colours of the Welsh flag, while official tournament programmes were being sold outside the stadium.

Keiran, 16, from Cardiff, said he was “going crazy already”, several hours ahead of the game as he bounced around waved a mini Wales flag and honked a horn, chanting the name of striker Hal Robson-Kanu.

“I’m very excited, very excited. Wales are going to win 2-1. I’ve got trust in them. I think Gareth Bale might score the first goal. He’s fast,” he said.

Meanwhile Steffan, 18, from Maesteg, northwest of Cardiff, was making even more specific predictions.

“I’m energetic. The fever pitch is up. I’ve got a £20 bet at 9/1 on Wales to beat Portugal 3-1. Kanu’s going to score. I’m buzzing,” he said.

– Backing from Prince of Wales –

Previous matches have been shown in a 6,000-capacity fanzone in Bute Park, but due to the overwhelming demand, the venue has been shifted to the Millennium Stadium.

The match will be broadcast live on its two giant screens, and a specially-erected 100-foot (30-metre) screen.

Some 20,000 free tickets were snapped up within 90 minutes of going online, so organisers released another 7,000 — which went in half an hour.

The capacity in the 74,500-seater stadium is restricted because the pitch is covered by a temporary speedway track laid down for Saturday’s Grand Prix — and due to the number of stewards organisers were able to get at such short notice.

Prince Charles, the Prince of Wales, sent a good luck message to manager Chris Coleman’s squad ahead of the match.

“As you prepare for what will be — so far — the most important night in the history of Welsh football, I did just want to send you all my special thoughts and wishes,” the heir to the British throne wrote.

“Throughout the whole championship, you have set an inspiring example of teamwork and sportsmanship and I have no doubt that in this latest game you will continue to give your country even greater cause for pride.

“Your historic achievements have already earned the support not only of Wales, but of the whole United Kingdom, and I hope you will know just how much we are all willing you on to further success.”

He signed off with: “Dymuniadau gorau ichi i gyd!” — “Best wishes to you all!” in Welsh.