While many of the bigger names struggled in the tough conditions, American Mo Martin, the world number 99, shot a second straight three under 69 to take a three shot lead at the British Open.
Beatriz Recari, the Spanish Solheim Cup player, shared second place at Royal Birkdale on three under with South Korea's Ryu So Yeon.
While the deep rough caused havoc, Californian Martin mastered the conditions with six birdies, including one at the long par five 18th where she was just off the green in two and two-putted for four.
"I think this is a fantastic course," said the 31-year-old who has won three times on the US Futures Tour but has yet to taste success in three seasons on the LPGA circuit.
"I don't hit it long but accuracy is my strength."
It's not been a happy start to the season for Recari. She's suffered with a bad hip and poor form and she arrived at Royal Birkdale with a wrist injury.
But most of her woes were banished when she put together a great five under par second round 67, the joint best of the Championship, and it included a string of three birdies at the end.
Recari had a fleeting visit to St Andrews last Sunday for a sponsor's day ahead of her trip to Birkdale.
But her flight from Scotland to England was delayed for a day and she blamed her struggles with heavy luggage for the wrist problem.
"I had to carry four pieces of luggage, said the 27-year-old.
"Two women tried to help me but I wouldn't let them because they are really heavy. But the men at Edinburgh airport were not very gentlemanly.
"Luckily the physios at Birkdale did a great job and my wrist was pain-free by Wednesday.
