The former world champion Tyson Gay equalled the second fastest 100 metres time ever when he clocked 9.69 seconds at the Shanghai Golden Grand Prix.
Gay's time equalled the world record set by Jamaican Usain Bolt when he won the 100 metres final at last year's Beijing Olympics.
Bolt reduced his mark to 9.58 seconds at this year's Berlin world championships with Gay second in 9.71.
Gay's team mate Carmelita Jeter overtook Marion Jones as the world's second fastest women over 100 metres when she clocked 10.64 seconds. Only the late Florence Griffith-Joyner has run faster.
Russian Yelena Isinbayeva failed in three attempts to improve her own pole vault world record of 5.06 metres.