Leona Maguire's hopes of an Olympic golf medal appear to be over after a nightmare back nine in the third round of the women's Olympic golf tournament saw her finish the day on level par.

Korea's Imbee Park tops the leaderboard after her round of 70 left here on -11, two shots clear of Australia's Lydia Ko and Gerina Piller of the USA on -9.

The first hole-in-one of her career lifted world number one Ko into medal contention. She defied the strong winds to bag an ace from 140 yards on the eighth in a front nine of 29.

While Ko thrived in the windy conditions, but Maguire and Meadow found the going tough.

A round of 65 yesterday put Maguire in contention as she broke into the top 25 and she started brightly today, claiming birdies on the second and fifth holes and getting to the turn at -5 as she looked poised to make a charge.

However things started to fall apart for Maguire as she bogeyed the par-4 12th and followed that up with further bogeys on the next two holes. 

The Cavan woman steadied the ship with a par on the 15th but two more bogeys left her well off the pace.

Ireland's other representative Stephanie Meadow had a mixed round, getting around in par.

Meadow recovered from a bogey on the first but hit four consecutive birdies from the fourth hole before a double bogey on the eighth halted her run.

Two bogeys and a birdie on the back nine left the Jordanstown women on +1 for the tournament.