Allyson Felix beat US compatriot Sanya Richards in a dead-heat finish in the women's 200 metres in which both timed 22.29 seconds.

Kenya's David Lekuta Rudisha triumped in the men's 800m in 1:44.85, while Nancy Jebet Langat made it another Kenyan win in the women's 1,500m in 4:13.63.

Veteran Virgilijus Alekna of Lithuania produced a 67.63m throw to defeat world champion Robert Harting of Germany in the men's discus.

Kerron Clement of the United States won the 400m hurdles in 48.11 seconds, while Jamaica's Brigitte Foster-Hylton won the women's 100m hurdles in 12.58, edging Dawn Harper of the United States (12.61).

Brittney Reese of the US captured the long jump in 7.08 metres, world championship silver medallist Betty Heidler of Germany threw a best of 72.03m to win the hammer throw, and world champion Yaroslav Rybakov of Russia dominated the high jump with a victory at 2.34m.

Ethiopia enjoyed a one-two in the women's 5,000m, with Meseret Defar (15:25.31) just getting the better of Tirunesh Dibaba (15:25.92) and Kenya's Vivian Cheruiyot (15:26.21).

Total prize money of just over $3 million is up for grabs at the two-day 36-event meeting, with $30,000 going to the winners of each competition and a bonus of $100,000 awarded for any athletes who beat a world record.