Ireland's Natalya Coyle lies in 12th position after completing her fencing ranking round in the modern pentathlon.
After a strong start, the 25-year-old dropped seven out of nine points in the middle of the session, but finished strongly.
Coyle ended the day with a record of 19 wins and 16 defeats after 35 contests, leaving her with a total of 214 points.
"I'm happy with it," she told RTÉ Sport afterwards. "I had a really, really good start and a little dip in the middle, but I pulled it back in the end, which I was hoping to do anyway.
It's so far so good in the modern pentathlon for Natalya Coyle https://t.co/L2aFQqwJQt #rterio2016 https://t.co/pv4DU5ph5w
— RTÉ Sport (@RTEsport) August 18, 2016
"It's a good finish. If I was told at the start I'd get that I'd have been happy. You always think about the hits you've left on the piste but pentathlon is never over until it's over.
"There's another four events tomorrow but I'll get back now and get some recovery, but I'm happy with it."
The modern pentathlon event includes fencing, swimming, showjumping, running and shooting.
The higher the athlete finishes in the ranking round, the better chance they have of picking up points in the main event, which takes place tomorrow. Coyle is straining at the leash to sreturn to action.
"I'm looking forward to it now, I can't wait," she added. "I'm dying to get back out there tomorrow. I'm feeling in really good shape."