London - The United States won the Olympic swimming women's 4x100m medley relay gold in a world record time of 3min 52.05sec on Saturday.
The American quartet of Missy Franklin, Rebecca Soni, Dana Vollmer and Allison Schmitt improved on the previous record of 3:52.19 set by China in winning the world title in Rome in 2009.
For 17-year-old Colorado high school student Franklin it was a fourth gold in the final women's pool event of the Games. She, Vollmer and Soni had all set individual world records at the London Aquatics Centre.
Australia's Emily Seebohm, Leisel Jones, Alicia Coutts and Melanie Schlanger took silver in 3:54.02 and Japan's Aya Terakawa, Satomi Suzuki, Yuka Kato and Haruka Ueda claimed the bronze in 3:55.73.