Nafissatou Thiam followed her world heptathlon high jump best with the top performance of the day in the shot put.
The Belgian opened with 14.41m and added half a metre to that with her final effort of 14.91m. It gave her the overall lead in the competition with 3107.
Jessica Ennis-Hill seemed disappointed not to throw beyond 14 metres, but her 13.86m effort was her best mark in a championship heptathlon since the 2012 Olympics.
Katarina Johnson-Thompson managed just 11.68m, dropping from first to sixth overall. But with her worst event out of the way, the Briton can be expected to climb back up the leaderboard in the four remaining events.
World indoor champion Brianne Theisen-Eaton managed a best throw of 13.45m to maintain her fifth-place position in the overall standings.
Other athletes moved up the leaderboard, though, including USA’s Barbara Nwaba. Her 14.81m heave moved her from 12th to ninth. Akela Jones went from fourth to third, thanks to her 14.09m effort.
European champion Anouk Vetter also produced one of the better marks of the competition. Her 14.78m throw bumped her up to 12th place overall.
Germany’s Carolin Schafer was one of the few athletes to set a PB in this event. Her 14.57m moved her into fourth place.
Ennis-Hill still looks on course to successfully defend her title. Teammate Johnson-Thompson also looks to be in a relatively safe medal position, but she cannot afford any more mistakes if she is to hold on to a medal position, as the likes of Theisen-Eaton, Schafer, Thiam and Vetter will all be ready to strike.
Jon Mulkeen for the IAAF