The New Zealand women's football team will play Britain on Wednesday in the opening event of the London Olympics.
Women's football in Britain rarely attracts crowds of more than 5000, but some 35,000 - 40,000 fans are expected to be at the match in Cardiff's MiIlennium stadium.
The Olympic football tournaments, involving 16 men's teams and 12 women's are too long to be accommodated within the Games timeframe, so they have to start before the opening ceremony on Friday.
The women's event begins at 4pm (BST). Other fixtures are in Coventry and Glasgow.
The men's matches begin on Thursday with games in Glasgow, Newcastle, Old Trafford in Manchester, Coventry and Cardiff.