LONDON - In their first Olympics, April Ross and Jennifer Kessy will play for the gold medal in an all-American beach volleyball final.

In their final Olympics together, Kerri Walsh Jennings and Misty May-Treanor are playing for something more.

"We want to seal the deal that we're the best team that's ever happened," Walsh Jennings said Tuesday night after the two-time gold medalists advanced to their third consecutive Olympic final with a 22-20, 22-20 victory over China. "I want to win tomorrow for us. … This will be our last match together, so we want to go out on top."

A few hours later, Kessy and Ross beat the top-seeded Brazilians in a persistent rain to join their fellow Californians in tonight's gold medal match. Prince Harry is expected to attend, following prime minister David Cameron by one night to the stands at Horse Guards Parade, which has also hosted such luminaries as Bill Gates, Prince Albert of Monaco, London Mayor Boris Johnson and a handful of NBA stars from the U.S. men's basketball team.

"I can't believe it. I only let myself picture it in my dreams," Ross said. "I never really expected it. I knew that we could do it, but the competition in the final four is so big."

Ross and Kessy rallied from a first-set loss and a four-point deficit in the second to beat reigning world champions Juliana and Larissa 15-21, 21-19, 15-12. The Brazilians will play in the third-place game against China's Xue Chen and Zhang Xi, who are trying to repeat their bronze medal finish from Beijing.

Despite a medal shutout by the American men, the United States has clinched multiple beach volleyball medals for the fourth time in five Olympics since it became a recognized sport in 1996.

"This has been everyone's goal since the beginning: to get the two U.S. teams in the final together," Kessy said. "I can't believe we're going to be on that podium - either gold or silver. It hasn't sunk in for me yet, probably because our job isn't done."

Already the most-decorated team in the brief history of Olympic beach volleyball, Walsh Jennings and May-Treanor are also guaranteed at least a silver medal. No one - man or woman - had ever won two beach volleyball gold medals before they became repeat champions in Beijing.

"I had a picture in my head at the beginning of the season of how I wanted us to play, and we're living that picture," Walsh Jennings said. "But it's not over yet."

Walsh Jennings and May-Treanor won gold medals in Athens and Beijing without ever losing a match - in their first two Olympics, they never even lost a set - and they ran their unbeaten streak to 20 straight Tuesday. But they gave up the first three points of the semifinal and fell behind 13-7 in the first set.