Jessica Ennis, of Britain, held a 50point lead after the third of the events in the heptathlon, the shot.
Best shot putter among the heptathletes was Jennifer Coogan, from Australia, who scored 661pts for her 12.00m put.
Ennis, who openly admits that the throws are her Achilles' heel, was happy with her 10.13m effort for 538pts and a three-event total of 2452.
In second place is Germany's Sarah Kern, with a total of 2402 after throwing 10.53m for 564pts.
Marina Gocharova, from Russia, moed into the medal positions, thanks to a 11.54m put that contributed 631pts to her total of 2387.
The 200m, the fourth and final event of the heptathlon's first day, is due to start around 6pm local time.
