Co-hosts Austria started their Euro 2008 campaign with a 1-0 defeat against Croatia in a Group B match played in Vienna on Sunday, dpa reported.
The only goal of the game was scored in the fourth minute by Luka Modic from the penalty spot.
Austria failed to impress in the early parts of the first half, but came back strongly towards the end of the game, but could not find the back of the net.
Germany and Poland meet in the other Group B match in Klagenfurt later Sunday.
On Saturday the other co-hosts, Switzerland, also lost their opening match, as they went down 1-0 to the Czech Republic in a Group A game in Basle.