Lydia Ko holds one-stroke lead in the New Zealand Women's Open

Lydia Ko took a one-stroke lead into the final round of the New Zealand Women's Open after shooting a 5-under 67 on Saturday.

The world No 1, who is defending her national title, started the day in a tie for fifth after an opening 69 and carded six birdies and just one bogey to edge ahead of Justine Dreher on eight under par.

French rookie Dreher fired a solid 70 to secure a place in Sunday's final group with teenage superstar Ko, while Scotland's Pamela Pretswell (70) is just two off the lead along with Danish duo Emily Kristine Pedersen (66) and Nanna Koerstz Madsen (68).

Ko, who holds the course record at Clearwater with a 61, played the front nine Saturday in four-under 32 before dropping her only shot of the day at the 13th.

Dreher birdied the par-five second moments later to join Ko in a share of the lead, but the home favourite reclaimed top spot when she hit her tee shot to seven feet on the par-three 16th and rolled in the putt for birdie.

"When you are at the top of the leaderboard, everyone is chasing you, but I would rather be leading than a few shots behind," Ko said. "I hit the ball much better today and had a lot of chances. I just need to focus on my game tomorrow."

Dreher, who only turned professional last year and has just $3,000 in career earnings, added: "I am excited and nervous. Just putting next to Lydia on Friday was a bit new. I am watching and learning from them."

Ko will start the final round as the overwhelming favourite to retain her title, but she expects a tough challenge from Dreher in the final group on Sunday.

"She copes with pressure well," Ko said. "If I think about what she is doing then there will be way too much thinking going on."