Ireland's Natalya Coyle lies in 12th position after the first day of the Modern Pentathlon in Rio.
Coyle, who is looking to improve on her ninth place finish in the London Olympics four years ago, scored 214 after a marathon opening fencing session.
Currently leading the event is Poland's Oktawia Nowacka on 262 with Germany's Lena Schoneborn in the silver medal position on 244 points and Canada's Melanie McCann in bronze with 238.
Thursday’s fencing action was split into 18 heats, 0-17, and within each heat bar one the athletes would take part in two fencing matches each, until they had duelled with every competitor in the 36-strong field.
Coyle's first duel was against Guatemala's Isabel Brand and she opened up with a victory - before going on win to 19 of her 36 contests.
The women’s competion reaches its climax on Friday with the final three events taking place througout the day.
First up is a 200m freestyle swim at 4.00pm, and Coyle is in the fourth heat of six. That is then followed by showjumping at 7.30pm with a combination of a 3km run and 10m shooting bringing things to a conclusion at 10pm.
Meanwhile in the men’s competition Arthur Lannigan O’Keefe is in 25th position after he scored 196 in the fencing.
Leading is Russia’s Alexander Lesun on 268 - an Olympic record - and he is well clear of Germany’s Patrick Dogue and Egypt’s Omar Elgeziry who both scored 238.
