Britain's Prince Harry took a tumble from his horse Sunday before his defeat in a New York polo match against the world's best known polo player, Argentina's Nacho Figueras. But it was all for a good cause - to benefit 400,000 children of an AIDS-ravaged African nation. The 25-year-old son of the late Princess Diana had a smile on his face as he got up and continued the contest, which Figueras' Black Watch team won 6-5 in overtime. The United States “has always protected the downtrodden, the poorest, those most in need of help in the world,” Harry said before the match. “And to me, this is what the United States stands for.” Proceeds from the day would go to American Friends of Sentebale, a charity set up in 2006 by Harry and Prince Seeiso of Lesotho for “the vulnerable children of Lesotho,” where many children are AIDS orphans. Harry said both he and the African prince wanted to follow the examples set by their mothers.