Jessica Zelinka has taken an early lead in the overall standings of the heptathlon thanks to an impressive display in the 100m hurdles.
The Canadian was dominant in the second heat of the morning, coming home in 12.83s to set a new Games record in the first event of the day.
Brianne Theisen-Eaton claimed second behind her teammate, with English duo Jessica Tappin and Jessica Taylor trailing their rivals in third and fourth, respectively.
Australia's Sophie Stanwell won the previous heat with a time of 14.18s, while England's Grace Clements earned second spot in the race to keep in touch with the leaders.