Trailing behind at the halfway turn, she pulled away from a tightly packed field with a more destructive force to hit the wall first in an American record of 58.33.

[2][3] Australia's Emily Seebohm started the race with a marginal lead over the rest of the field, but faded down the stretch to settle only for the silver in 58.68.

[4][5] Meanwhile, Japan's Aya Terakawa grabbed the bronze in an Asian record of 58.83, holding off the fast-charging Russian swimmer Anastasia Zuyeva to a fourth spot in 59.00.

[7][8][9] Earlier in the prelims, Seebohm blitzed the field from heat four to lead all swimmers with a sterling Olympic and Oceanian record in 58.23, shaving 0.54 seconds off the standard set by Zimbabwe's Kirsty Coventry in Beijing four years earlier.

[10][11] Coventry, double Olympic silver medalist, missed a chance to reach the final roster with a fourteenth-place effort (1:00.39) from the semifinals.