Sawa, who led Japan's women to an astonishing World Cup triumph in Germany last year, posed for photos with triple men's winner Lionel Messi while dressed in a traditional kimono.
"My first thought was that the trophy felt so heavy," Sawa told Japan's NHK television on Tuesday. "It's humbling to write a new page in Japanese football history.
"It still hasn't sunk in," added the 33-year-old, whose brilliance in Germany last year halted a run of five successive wins for Brazilian hot shot Martha.
"Just for making it among the nominees, I wanted to say 'Well done!' to myself. When I went up to get the award my heart was pounding and I was sweating. It was a surprise to win."
Japan coach Norio Sasaki won the women's coach of the year at a gala FIFA ceremony on Monday.
Sasaki had shown his team harrowing photos of the devastation wrought by last year's deadly earthquake and tsunami in northeast Japan before their matches at the World Cup.
"This award is a testament to the unity of Japan," said Sasaki, whose team upset Germany and Sweden before a dramatic victory on penalties over the United States in the final.
"It was emotional to accept the award after all the support shown for Japan following the earthquake."
Japan's women gave the nation a psychological lift as a nuclear crisis raged back after the giant tsunami, triggered by the quake, destroyed a power plant north of Tokyo.
Named after a frilly pink flower, Japan's "Nadeshiko" embodied the iron-willed spirit of a nation united in its battle to recover from the March 11 disaster.
"I feel blessed," said Japan Football Association (JFA) president Junji Ogura. "Sawa and Sasaki winning are both firsts for Asia. It's amazing.
"It also means, however, Japan's women will now become a target. Everyone will be trying to beat them at the Olympics in London this year. It's an exciting new challenge."
The JFA capped a special night for Japan by picking up the Fair Play award.
