Great Britain's Louis Hazel dropped into fourth place in the third heat of the 100m hurdles of the women's heptathlon.
The British hopeful recorded a time of 13.42s after taking the lead from the start but slipped slightly towards the finish line to come in at fourth.
Hanna Melnychenko clinched the fastest time of 13.32s for Ukraine, with Switzerland's Ellen Sprunger finishing third in the heat to get off to a positive start.
Katerina Johnson-Thompson and Jessica Ennis are due up next in the next two heats for the Brits.