By Estelle Shirbon

LONDON (Reuters) - The top headline in beach volleyball at the 2012 London Games was the third straight Olympic title won by the U.S. women's pair, but the big picture was about a changing of the guard.

The 15,000-seat Olympic stadium built at Horse Guards Parade in the heart of the British capital was a dramatic location for Misty May-Treanor and Kerri Walsh to accomplish their feat, with Big Ben and the London Eye lighting up the sky.

No other team, men or women, have retained an Olympic beach volleyball title, let alone won a third.

"It's like an out-of-body experience. You're just floating and you're like 'what's going on?'," said May-Treanor minutes after she and Walsh beat compatriots April Ross and Jennifer Kessy in the final.

The silver medalists could only look on in wonder.

"They are the best team of all time," said Kessy.

"Hats off to them because that is just ridiculous," said Ross.

The London Games were only the fifth where beach volleyball has been played for medals. Until these Games, the United States and Brazil had won all the golds bar one, the women's gold at Sydney 2000 that went to an Australian pair.

The top two nations did well again in London, with U.S. women taking both gold and silver and Brazil taking the men's silver and the women's bronze.

Germans Julius Brink and Jonas Reckermann won the men's gold, a breakthrough that reflected the increasing strength of European teams challenging the American-Brazilian duopoly.

"I hope that this will bring up the European sport. It's great to be the ones who did it for Europe," said Reckermann.

NEW START

Both U.S. men's pairs were knocked out well before the medal matches, one by an Italian team and the other by Latvians. With the field clearer, teams from Germany, Brazil, Latvia and the Netherlands made the semi-finals. The Latvians, Martins Plavins and Janis Smedins, went on to take bronze.

Players said the results did not reflect any deep crisis in American beach volleyball but the fact that competition was getting tougher.

"Everybody's getting better. The tour's so tough these days," said U.S. player Sean Rosenthal, who had been considered a strong medal contender until he and Jake Gibb were knocked out by Plavins and Smedins.

Latvia, a tiny Baltic state, emerged in London as an unlikely force in a sport usually associated with sunnier places. Two Latvian men's pairs competed and did better than the U.S. teams.

Generational change is also afoot.

The London Games marked the beginning of the end for the first wave of beach volleyball Olympians, many of whom enjoyed extra-long careers that will probably not be possible in future as the field widens and strengthens.

May-Treanor, 35, has now retired from competition. Silver medalist Kessy, 35, announced she does not intend to compete at the next Summer Games in Rio de Janeiro in 2016.

The curtain also fell in London on the career of five-time Olympian Natalie Cook of Australia, 37, who won gold in Sydney.

In the men's game, Brazilian veteran Emanuel, 39, won silver with his team mate Alison Cerutti, 27. A five-time Olympian, Emanuel had won gold in Athens in 2004 and bronze in Beijing in 2008 with his former team mate Ricardo Santos.

Emanuel has not ruled out competing in Rio but sounded skeptical about his prospects. He said it was time for Alison's generation to take over and predicted a major reshuffle of pairings in Brazil, the United States and elsewhere before Rio.

"This will be a new start for sure," said Emanuel.

(Editing by Mark Meadows)