Football fans will be able to watch Cardiff City's Championship play off-final at Wembley on a big screen in Cardiff Bay.
Seven thousand people will be allowed into Roald Dahl Plass on Saturday to see if the Bluebirds beat Blackpool to clinch promotion to the Premier League.
Admission will be free on a first come first served basis from 1300 BST. The screen will be showing live coverage of all the big match build-up from 1400 BST, staying on air until half an hour after the game ends.
For health and safety reasons no-one will be allowed to take alcohol onto the site.