Kayla Harrison wins women's 78-kilogram Olympic judo gold, U.S.' first-ever gold in sport

Gold medalist Kayla Harrison of the United States in the Women's -78 kg Judo on Day 6 of the London 2012 Olympic Games at ExCeL on August 2, 2012 in London, England. / Laurence Griffiths/Getty Images

(CBS/AP) LONDON - Kayla Harrison gave the U.S. its first judo gold medal in Olympic history, taking the 78-kilogram title Thursday at the London Games.

Harrison, 22, defeated Britain's Gemma Gibbons in a final she dominated from the start, getting a stronger grip on Gibbons and managing to throw her twice.

Her medal is the U.S.' second in judo this week: Teammate Marti Malloy won a bronze in the women's 57-kilogram division.

Harrison, world No. 4 and a former world champion, was in top form, dispatching many of her opponents with a match-ending ippon move, one in less than a minute. Harrison said she was focused on the gold.

"This is my purpose," she said.

Harrison, whose story of sexual abuse by her former coach as a young teenager has been well documented in the media, received the honor to a raucous round of cheers, CBSSports.com's Matt Moore reports.

The bronze medals were won by Audrey Tcheumeo of France and Mayra Aguiar of Brazil.