US first lady Michelle Obama was named the world's most powerful woman by Forbes magazine, toppling German Chancellor Angela Merkel after four years on top.
Performance artist Lady Gaga made the top 10, coming in seventh.
Merkel was relegated to the fourth position, preceded by Kraft Foods Inc chief executive Irene Rosenfeld and talk show host Oprah Winfrey at second and third place, respectively.
Obama has "made the office of first lady her own," Forbes said. While more involved in policy than her predecessor, Laura Bush, Obama has stayed away from "hard policy," unlike Hillary Clinton did when she was first lady.
"A fashion icon and an athletic mother of two, she's Jackie Kennedy with a law degree from Harvard and street sense from Chicago's South Side," Forbes said.
US Secretary of State Hillary Rodham Clinton came in fifth, followed by Pepsi Co chief executive Indra Nooyi and Lady Gaga.
The chief executive of Australia's Westpac Banking Corp, Gail Kelly, was the only other non-US power woman in the magazine's top 10 list.
Singer Beyonce Knowles and talk show host Ellen DeGeneres completed the top 10.