New York ? 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.

Britain's Prince Harry stands with members of the United States military at the Achilles Hope and Possibility Race at New York’s Central Park on Sunday.

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 fell off his polo pony in the first half of the third annual Veuve Clicquot Polo Classic on Governor’s Island.

But he had a smile on his face as he got up and continued the contest, which Figueras’ Black Watch team won 6-5 in overtime. At first, the prince’s Black Rock foursome was ahead, with Harry scoring an early 2 points, despite his fall.

“I think his horse got spooked, or something,” Figueras told The Associated Press, adding, “It was a very tight match — right till the end, we didn’t know who was going to win so it was very exciting to play.”

But polo was not the main point of the day.

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.”

Harry played as part of his pledge to continue his mother’s work. Princess Diana, who was often photographed embracing HIV-positive mothers and children, died in 1997 in a Paris car crash.

Sunday’s heat, topping 90 degrees, “is a welcome relief after the snow and ice of Lesotho, where I was last week,” her son said of the southern African nation where he said he took his brother, Prince William, to show him the work of his charity.

Harry’s three-day visit to New York began Friday at the West Point Military Academy north of the city, followed by UNICEF on Saturday and throwing the first pitch at a Mets game.