The 18th World Cup got off to a thrilling start as hosts Germany defeated Costa Rica 4-2 under clear blue skies this evening in the highest-scoring opening match in the history of the tournament.

Although deprived of captain Michael Ballack through injury, the Germans triumphed in front of 66,000 fans at Munich's futuristic Allianz Arena, with around a billion more watching on television around the world.

The game passed off with no major security problems, to the relief of organisers. Some 250,000 police officers are tasked with protecting the finals from hooliganism and terrorism.

Today's Group A game was the first of 64 matches spread around 12 host cities in the month-long tournament, culminating in the final at Berlin's Olympiastadion on July 9th.

Germany coach Juergen Klinsmann, under immense pressure from a host nation of 80 million which takes its football seriously, pronounced himself satisfied with his team's start. "We can take a lot of positive things out of today," he said.

Poland are currently trailing Ecuador by one goal in the western city of Gelsenkirchen in the other Group A game.

Ahead of the opening match, a spectacle of dancers in lederhosen and straw-skirts banged on drums and rang giant cow bells under clear blue skies as an emotional crowd waved flags from the 32 participating countries.

"This is the most beautiful game in the world and I am here at the very start of it," said German fan Klaus Breitmann, draped in his national flag and wearing a black-red-gold wig.

"This is the biggest party in the world and I am invited." Audience figures for the whole tournament, the world's most watched sporting event, are expected to reach nearly 30 billion.