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The rain was familiar to Misty May-Treanor and Kerri Walsh.

Losing a set a set at the Olympics? Not so much.

The American beach volleyball pair dropped a set for the first time ever at the Summer Games, but won the next two to knock off Austrian sisters Stefanie and Doris Schwaiger to move into the knockout round.

They played in front of NBA stars Carmelo Anthony, Kevin Durant and James Harden, who were introduced to the Horse Guards Parade crowd before the match.

"Beach volleyball game crackin...let's go Misty and Kerri!!" Durant tweeted near the start.

It took a little while.

A sloppy start by the Americans allowed the Austrians to open with a 7-1 run on points. May-Treanor hit a spike right into the net not long before they called a timeout.

They trimmed the margin but lost 21-17, ending their 31-set winning streak at the Olympics.

No problem. The second set took only 16 minutes, the Americans winning it 21-8.

In the third set, Walsh's spike to make it 8-6 drew "oohs" from the typically raucous crows that packs this temporary arena near Buckingham Palace with views of Big Ben and the London Eye ferris wheel.

"We want to play in front of this crowd right here," Anthony said earlier.

Many in the packed venue also booed when Walsh was called on a net touch and argued.

It drew the Austrians within 9-7, but May-Treanor followed with a hard spike and the Americans went on to win the set 15-10 with the Austrians hitting into the net on match point.

They moved to 3-0 here and into the round of 16.

"It probably wasn't our best, but we stick together through thick and thin. Austria are a good team and our pool is pretty tough," said May-Treanor. "We've seen a lot of tight matches out here and that's a test for us. I think the match was a learning process for us. We wanted to win in two sets, but a victory is a victory."

Though it drizzled for periods during the match, it was nothing approaching the final in Beijing, when May-Treanor and Walsh won their second straight Olympic gold medal in a downpour