The flags of the 32 countries participating in this year's World Cup are seen during opening festivities at Munich's World Cup Stadium, Friday

The World Cup football (soccer) tournament is under way in Germany with the host nation playing Costa Rica in Munich.

After an elaborate ceremony, the kickoff started at 18 hours UTC in front of a capacity crowd in Munich's New Stadium, the home field of Bayern Munich.

Germany took a 1-0 lead on a sixth minute goal by Philipp Lahm. Costa Rica tied the match six minutes later on a goal from Paulo Wanchope. Miroslav Klose scored Germany's second goal in the 17th minute.

Poland and Ecuador, the other Group-A teams, will meet later Friday) in Gelsenkirchen.

Teams from 32 qualifying nations will compete in the tournament, which is held every four years in a different country. The teams are divided into eight groups of four in round-robin play, so each team is guaranteed three games. The top two teams in each group, or 16 nations, will then move on to the single elimination, or knockout, phase.

The tournament will be held in 12 cities across Germany. Defending champion Brazil has been picked by many to take home the trophy. Brazil will be the last of the 32 teams to play a first-round match, taking on Croatia in Group-F next Tuesday.