A greek website reproduces the 10 biggest upsets in football (international games) Unfortunately they don`t mention the source
10) 1950 WC Brazil-Uruguay 1-2
9) 2002 WC S.Korea-Italy 2-1
1954 WC Hungary-W. Germany 2-3
7) 1982 WC N.Ireland- Spain 1-0
6) 1966 WC N.Korea-Italy 1-0
5) 1986 Copa Africa Egypt-Senegal 0-1
4) 1990 WC Cameroon-Argentina 1-0
3) Euro 2004 Greece wins the trophy
2) 2002 WC Senegal-France 1-0
1) 1950 WC USA-Italy 1-0