Chinese youngster Ye Shiwen unleashed a withering burst to claim Olympic gold in the women's 400m medley in world record time on Saturday.
The 16-year-old overwhelmed American world champion Elizabeth Beisel to win the final in four minutes 28.43 seconds to cap a glittering night for China in the pool following Sun Yang's victory in the men's 400m freestyle.
Ye put in a storming final freestyle leg to shatter the previous record of 4:29.45, set by Australian Stephanie Rice en route to gold at the Beijing Games four years ago.
So supercharged was Ye's finish that she powered under the world record on the back of a 28.93sec final lap to leave her rivals in her wake.
Beisel finished with silver in 4:31.27 with Ye's teammate Li Xuanxu taking the bronze in 4:32.91.
Defending champion Rice trailed in sixth in 4:35.49 with British hope and world silver medallist Hannah Miley fifth in 4:34.17.
"I think under the circumstances, it proves I am not fit enough to back up two top-class swims, I didn't really cruise through the heats," said Rice.
"I am disappointed, I can't deny that. I put in a solid swim, just the time wasn't good enough."
A long-term shoulder injury, which requires treatment after every training session, has hampered the 24-year-old Rice's preparations for the defence of her two Olympic medley titles.
Miley accepted her defeat before a cheering home crowd in good grace.
"I'm feeling all right. Most of the media are expecting me to be depressed and down and in tears," Miley said.
"I know it wasn't the result that the (British) public wanted, which was a medal, but that was something that they decided to put on themselves, to that expectation of me.
"For me, my target was to try to give the best performance that I could, and I can honestly say that I gave that absolutely 100 percent."