US National Security Adviser Condoleezza Rice is the world's most powerful woman, according to a top 100 list published by Forbes magazine.
Ms Rice has "silver-tongued diplomacy and a steely nerve"
China's Vice-Premier, Wu Yi, was second in the list, followed by Sonia Gandhi, head of India's ruling Congress Party.
The leading businesswoman was Hewlett-Packard chairwoman, Carly Fiorina.
Forbes said it used a scorecard involving title, curriculum vitae, media mentions and the economic power of a candidate's sphere of influence.
Forbes said that Ms Rice, 49, had "played a key, behind-the-scenes role in helping to steer the United States through two wars, as well as the resulting controversies".
Hillary Rodham Clinton
Sandra Day O'Connor
Ruth Bader Ginsburg
Carleton "Carly" S Fiorina
The magazine said Ms Wu, 65, was a "rising star" in China's Communist Party.
It said she had impressed party leaders when handling trade agreements with Russia and the delicate negotiations for China's accession to the World Trade Organisation.
Italian-born Sonia Gandhi, 57, led Congress to election victory in Indian elections in May but won widespread praise for stepping aside to let Manmohan Singh become premier.
The importance of women in Asian politics was underscored with the presence in the top 10 of Indonesian President Megawati Sukarnoputri and Philippines counterpart Gloria Macapagal-Arroyo.
US President George W Bush's wife, Laura, was fourth on the list, which also included two US Supreme Court justices in its top 10 - Sandra Day O'Connor and Ruth Bader Ginsburg.
Forbes said the list made "a refreshing break from the conventional wisdom about women and power".
Apart from politicians, the list included heiresses, entertainment figures and royalty.
Britain's Queen Elizabeth ranked 22, a long way behind leading royal figure Queen Rania of Jordan at 13 and even one place behind former British premier Baroness Thatcher.
In the entertainment sphere, the key figures included Oprah Winfrey at 62 and JK Rowling, author of the Harry Potter series, at 85.
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