By Martyn Herman

LONDON (Reuters) - Passions ran high at London's Earls Court on Wednesday as the latest chapter of one of the world's great sporting rivalries saw Brazil overwhelm Argentina to reach the semi-finals of the men's Olympic volleyball tournament.

It was the first part of a juicy double-header between the south American powerhouses who were also locking horns across London in the basketball quarter-finals later.

Brazilians vastly outnumbered their Argentine counterparts inside the cavernous arena that, for an hour or so, could have been in Rio de Janeiro.

The distinctive yellow and green was splashed all around the 12,000-capacity arena, with fans, some wearing matching wigs, draped in Brazilian flags. Breaks in a play were filled with the samba rhythm as drummers added to the carnival atmosphere.

Outside, fans carrying cardboard signs saying "Tickets PLEASE! or "tickets to swap" walked around desperately trying to find a way to watch the day's opening quarter-final. Many were left disappointed despite plenty of empty seats inside.

"We love the Argentineans," joked ticket holder Fernando Carvalho, a Brazilian studying in London, as he rushed to find his seat. "Especially when we throw them on the barbecue!"

Leandro Santos, who had travelled from Sao Paulo especially to watch the volleyball tournament in which both Brazil's men and women have chances for gold, summed up the rivalry.

"When we play Argentina it doesn't matter if it's soccer, basketball, volleyball, cards or dominoes, there's always a lot of pride at stake," Santos, wearing a Corinthians' soccer shirt, said. "It's never friendly."

The soccer pitch is the natural environment for the two nations that gave the world the likes of Pele, Diego Maradona, Ronaldo and Lionel Messi but the Olympics throws them together in different sports. Continued...