The city closed the so-called Fan Mile to traffic at the landmark symbol of national unity to make way for supporters cheering on the German side in its showdown against Argentina.

Crowds surpassed the 200,000 maximum capacity hours before the match, an event spokeswoman said.

Braving a driving downpour, vendors did a booming trade in currywurst, a local speciality of sausage smothered in spicy ketchup, and plastic cups of beer.

Germans who have waited since 1990 for the Mannschaft to bring home a fourth World Cup title said they believed this was their year.

Manuel, a 19-year-old from Brandenburg state outside Berlin, smiled with his cheeks painted in the German colours.

"I think it's going to be 2-0 for Germany," he said, adding that he had been a regular part of the Fan Mile during the month-long tournament.

"I have been here for five hours," he said in the late afternoon, fearful of missing out when the authorities close the gates to prevent overcrowding.

Normally a rare sight due to the country's dark history, German flags fluttered from street lamps, honking cars snaking through city streets and supporters' shoulders, worn like superhero capes.

Revellers young and old, male and female donned mohawk wigs, bunny ears and cowboy hats in the national colours, chanting "Deutschland, oh-ho."

A group of disabled fans in wheelchairs sang their hearts out as they made their way through the masses.

"I bet Germany will win 1-0," said Eda Sobota, 70, with a Hawaiian-style garland of plastic flowers in the German colours hanging from her neck.

"I'm from East Germany and have supported the all-German team since reunification" in 1990, she said.

- First since reunification -

Stefan Winkler, a German who works for a bank in London, was also bullish as he sipped a beer under one of several giant screens where the match will be broadcast.

"I say it will be 3-2 for Germany," the 34-year-old said.

"If we win it will be something special -- the first time for Germany since reunification," recalling West Germany's victory over Argentina just months before the country overcame its Cold War division.

Valentin Papp, wearing an Argentina jersey, cut a lonely figure in an eastern district of Berlin as he waited for a few friends to watch the match at the Cultural Brewery, a former beer factory turned events centre.

"I'm very anxious - I can't wait for the game to start," said the 24-year-old Argentine law student.

"I have exams this week but I couldn't concentrate on anything but football."

Papp had been at the Fan Mile earlier in the day.

"A lot of German people said things about my jersey but they were respectful. That could change later when people start drinking."

Thirteen-year-old friends Antonia Siedentop and Gina Ibsch made the trip to the capital with their parents from their village in the Harz mountains in the centre of the country.

"We just had to be here to support the team," Siedentop said, quivering with excitement.