Xinhua
The United States won the mixed 4x100m medley relay in a new world record of three minutes, 37.43 seconds on Saturday, knocking 0.15 seconds off the previous record held by Britain.
China took the silver medal in 3:37.55, while Australia claimed bronze with 3:38.76.
A thrilling race saw the US narrowly lead after the backstroke, before a strong second leg on the breaststroke from Qin Haiyang put China in front.
The Americans reclaimed the lead on the butterfly, but the two teams were virtually neck and neck until American anchor Torri Huske found just enough in freestyle to hold off Yang Junxuan, who might have overtaken her if the race had been ten meters longer.