Rebecca Adlington failed to repeat the heroics of Beijing in front of her home crowd, finishing third in the 800m freestyle at the Aquatic Centre on Friday.
Adlington struggled to keep pace with her 15-year-old opponent and finished third
Katie Ledecky, the 15-year-old swimming for Team US, set a blistering pace, taking the lead early on. She remained ahead for the entire race, despite the best efforts of the crowd to inspire a fight back from Adlington.
The Duke of Cambridge and Prince Harry were among the crowds, as were member of the US basketball team, including LeBron James.
After the race, Adlington said: "That was so painful, it gets more painful the older I get.
On the new Olympic champion, Adlington said: "She went out so fast, she is absolutely incredible," adding: "The pressure, the expectations and everything going into this meet was difficult."
Spain's Mireia Belmonte García finished in silver.
Adlington, who took home gold in both 400m and 800m events in 2008, now has four Olympic medals.
The 23-year-old from Mansfield, Nottinghamshire, won bronze in the 400m last week, with bronze in Friday's swim securing her place in British Olympic history.
