Bikini-clad women served up a shocker in more ways than one outside the back window of British Prime Minister David Cameron to open London Olympic beach volleyball competition yesterday.

Horse Guards Parade, a venerable park area dating to 1745 where the Queen’s pageantry-filled official birthday party is staged, had nearly 15,000 people packing temporary stands for a spectacle on sand unlike any other.

“You guys are at the most iconic venue,” stadium announcer Mark Perkins told the crowd as he encouraged cheers.

“Let Mr Cameron hear you. Beach volleyball at Horse Guards Parade – who would have thought it?”

And in the first match, 2008 Olympic bronze medallists Xue Chen and Zhang Xi of China, ranked second in the world, were upset by Russia’s Anastasia Vasina and Anna Vozakova 18-21, 21-14, 16-14.

Whitehall government office buildings loomed in the background along with Cameron’s residence at No. 10 Downing Street and the top half of the London Eye ferris wheel.

Buckingham Palace, Big Ben, the Houses of Parliament and Westminster Abbey were just down the road.

“Maybe the Queen heard you then,” Perkins enthused after a loud cheer from the crowd.