Team GB's Samantha Murray has jumped from 16th to third after the swimming heats of the modern pentathlon.
Murray had endured an indifferent start to the event but she responded with the second fastest time in the swimming discipline.
Hungary's Adrienn Toth currently holds a 16-point lead over Brazil's Yane Marques, with Murray a further 20 points back in third.
Team GB's Mhairi Spence is currently in ninth place.
The riding discipline takes place later this afternoon.
