US Open: Lydia Ko moves into lead at CordeValle

Ko led going into the final round of last major - the PGA - but lost in a play-off to Canada's Brooke Henderson

World number one Lydia Ko birdied her last hole to establish a one-shot lead going into the final round of the US Women's Open in California.

Ko, 19, was in a group of players at six-under on the 18th tee, but rolled in a nine-foot birdie putt for a 70.

The New Zealander is one clear of overnight leader Sung Hyun Park (74) and Eun Hee Ji (70), both of Korea.

England's Jodie Ewart Shadoff and Scotland's Catriona Matthew are tied for 20th place on level par.

Ko was tied for 52nd place after an opening 73 at CordeValle, but a second-round 66 moved her into contention and three birdies on Saturday edged her into the lead.

"People say it's moving day on Saturday, but it was really tough out there because the course is drying out, firming up," Ko said.

"In major championships, sometimes a par is a good score and you have to walk off and forget about the bad shots."