American Kristin Armstrong capped her return to the sport following the birth of her baby by successfully defending the women's Olympic time trial crown here on Wednesday. Germany's Judith Arndt finished second with Russian Olga Zabelinskaya in third taking the bronze after the 29 km race against the clock around Hampton Court Palace. Armstrong, who returned to cycling after the birth of her baby nearly two years ago in a deliberate bid to defend her crown, clocked a winning time of 37min 34sec. World time trial champion Arndt took the silver in a time of 37:50 while Zabelinskaya, already the winner of a road race bronze on Sunday, took her second medal of the Games in a time of 37:57. Danish-born New Zealander Linda Villumsen finished just two seconds off the bronze medal in fourth with Canadian Clara Hughes in fifth.