Brittany Long, another American, also shot a 71 despite a double-bogey 6 on the 15th, in a round that also included five birdies and two bogeys.

Shin bogeyed the second hole Thursday but recovered with birdies on No. 3 and 18, while Inkster mixed five birdies with four bogeys in an inconsistent round. The 50-year-old American dropped shots on each of the first two holes, before birdies on four of the next six.

She dropped strokes at the 10th and 13th on the way home picking up just one birdie at the 11th.

"It felt good to shoot 1 under in difficult conditions," said Inkster, who has won seven majors but is still looking for her first British Open title. "It's tough out there but it's good to know I can still do it and I'd love to do it for three more rounds." A group of players including Laura Davies of England were one shot behind, while three-time champion Karrie Webb of Australia were among four players who carded 73.

Davies played solidly throughout but said she should have converted more opportunities.

"I missed some chances coming in to be honest. I missed about a four-footer for birdie on 18 and three holes before that I left a three-foot putt short," Davies said. "But having said that I'm delighted with that start." Webb was at 3 under at the turn before four bogeys on the back nine.