Four-time Olympic gold medallist Allyson Felix made a disappointing return from injury at the second meeting of the Diamond League season, coming fifth in the 400m in Shanghai.
Jamaican Novlene Williams-Mills ran in 50.31 seconds to beat Botswanan Amantle Montsho, while Felix finished in 50.81.
American Justin Gatlin won the 100m in 9.92, the world's fastest time this year, with Dwain Chambers seventh.
Chambers' fellow Briton Phillips Idowu was sixth in the men's triple jump.
Russian Lyukman Adams claimed first with a jump of 17.10 metres , while Idowu, 35, posted a 16.47.
British record holder Steve Lewis finished eighth in the pole vault, won by Frenchman Renaud Lavillenie with a clearance of 5.92 metres.
American Felix, 28, had targeted a quick return to the form that saw her crowned 200m Olympic champion in 2012, but was unable to follow the pace in her first race since injuring a hamstring at the 2013 World Championships in Moscow.
Gatlin, Olympic 100m gold medallist in 2004, finished 0.2 seconds ahead of Jamaica's Nesta Carter, while his compatriot Michael Rodgers was third.
"I know I did a good time but was not thinking 9.92," he said. "I just wanted to put a good race together. I have much more left in the tank, I felt I made it look easy."
In the women's long jump, Blessing Okagbare of Nigeria set a new meeting record of 6.86 metres to claim first, while 25-year-old Briton Shara Proctor finished ninth.
Okagbare, 25, also triumphed in the 200m, setting another new meeting record of 22.36 to edge Anthonique Strachan of Bahamas.
"I was just going out there to do my best," she said. "If I execute properly, I wouldn't get less than a win.''