New Zealand shot putter Valerie Adams had to settle for second at the latest Diamond League event in Birmingham.
Adams' best throw of 19.63 metres was 10 centimetres behind the American winner, Tia Brooks.
Adam's Olympic team-mate Nick Willis was a distant third in the 15-hundred metres, almost five seconds behind the winner from Kenya, Asbel Kiprop.
Double Olympic champion Mo Farah continued his build-up to the Rio Games by breaking David Moorcroft's 34-year-old British record in the 3,000 metres.
Farah, the 5,000 and 10,000m gold medallist at the 2012 London Olympics, won in seven minutes 32.62 seconds beating Moorcroft's 1982 time of 7:32.79.
There was a minute's applause at the Birmingham stadium for the former Olympic and world heavyweight champion, Muhammad Ali, who died on Saturday aged 74.