Laura Davies slid home a 30-foot birdie putt at the 18th to share a three-way tie for the lead on five-under-par 67 after the first round of the McDonald's LPGA Championship at Bulle Rock in Maryland.
England's two-time former winner was the best of the British - with Glasgow's Janice Moodie the best of the three Scots on 73.
North Berwick's Catriona Matthew, who has had a dream run with four top-three finishes this season, had a 75 that was blighted by three bogeys in a row from the fifth (her 14th) but then the only birdie of the day came at the long eighth.
Davies, a two-time former winner, had half a dozen birdies and finished alongside two Americans, Laura Diaz and Natalie Gulbis, and a shot ahead of a group of four that included the player who remains the overwhelming favourite, world No.1 Annika Sorenstam. Just another shot back was 15-year-old American amateur Michelle Wie as the second major of the women's season started to shape up as an intriguing contest of the new generation of youngsters and the experienced veterans.
Davies' round was interrupted by a weather delay and another thunderstorm threatened as she left the course.
"It was good to get in before another delay and the putt at the last was a great way to finish," she said.
"Putting has let me down this season but I've got my caddie reading the lines and it seems to be working. I'm hitting the ball great so it's all coming together."
Sorenstam, meantime, said she had enjoyed watching her 22-year-old playing partner, Gulbis, make five birdies over the final five holes, but she was also keen to point out that shooting the low round on a Thursday was not what majors are all about.
"This is only about 10 per cent along the way," she suggested. "It's the weekend when the work really starts. But I'm very pleased with my start. It was a really solid round."
The only slight glimpse of frailty came at her first hole, the 373-yard tenth. She pushed her tee shot into the rough that everyone had deemed so penal and then tugged the recovery left of the green. Her chip left her six feet away, but she calmly holed out for par.
Her longest putt of the day came at the next hole - the 596-yard 11th is the longest in women's golf - where she holed from 13-feet for the first of the four birdies.