ST ANDREWS, August 4, 2013 (AFP) - In 2008, the American won all five matches over the Home of Golf's famous links in leading her country to victory over Great Britain and Ireland in the Curtis Cup.
Five years on and the 28-year-old winner of the 2011 Kraft Nabisco Championship collected her second major with a final round 72 for eight under 280.
Choi Na Yeon and Park Hee Young both shot 73 and were joint runners-up on six under.
But there was disappointment for their fellow South Korean, Park Inbee, who had been aiming to become the first golfer to win four majors in one calendar year.
The world number one's attempt for a place in the record books petered out in a whimper.
The Seoul 25-year-old went into the final round nine off the lead and after reaching the turn in 41 she went on to post a disappointing 78 for six over par and joint 42nd.
"I've gone through four rounds of intense pressure and I'm sort of glad it is over," said Park.
"I enjoyed it, but it was very tough. I almost feel relieved it is all over. It was hard being the centre of attention all week and I feel exhausted.
"Unless I do go on and win four majors in a row then I think I'll always remember this moment. It is something not many get to experience and so I was very lucky."
Three behind Choi following a run of bogeys at the start of the second half, Lewis, the world number two produced some magic over the final stretch in the wild and windy conditions.
At the famous Road Hole -- the 17th -- she hit her second shot to tap-in range and then she holed a 30-foot birdie putt at the last to set a target that no one else could match.
"This is unbelievable," said Lewis. "I fought so hard over every shot all day and then it happened so fast at the end. A couple of birdies and it was over.
"The second shot to two feet at the 17th with a five iron was probably the best shot of my career. That got me to seven under and I thought that might be good enough for a play-off. Then to birdie 18 was incredible.
"It was such a tough day having to play 36 holes. I was up at 4.30am. But I love this course. All the history and, because of the Curtis Cup, I had played the course so often.
"I am so comfortable here at the Old Course and I almost feel this victory was meant to be."
Choi, last year's US Women's Open Champion, bogeyed the 13th, dropped another shot by three-putting the 14th and another bogey at 17th left her two adrift.
With play having been suspended around lunchtime on Saturday due to high winds, all the leaders had to pack 36-holes into the final day.
After the third round, America's Morgan Pressel led on nine under after a 71.
Lewis had a 69 for eight under and Choi (75), the halfway leader, and Park (70) were in a group tied for third on seven under.
Pressel, hampered by a four-putt double-bogey at the 12th, had a final round 76 and finished tied for fourth on five under with Norway's Suzann Pettersen (74).
On the same mark as Park, New Zealand's 16-year-old Lydia Ko and England's 17-year-old Georgia Hall shared the Smyth Salver for the leading amateur.
Ko, who was joint 17th at the British Open at Hoylake and top amateur last year, closed with a 74 and Hall, the British amateur Champion, had a 77.
Leading scores after the completion of the weather-delayed third round at the women's British Open at St andrews on Sunday (par 72):
207 - Morgan Pressel (USA) 66 70 71
208 - Stacy Lewis (USA) 67 72 69
209 - Park Hee Young (KOR) 70 69 70, Suzann Pettersen (NOR) 70 67 72, Miki Saiki (JPN) 69 66 74, Choi Na Yeon 67 67 75
210 - Catriona Matthew (GBR) 68 74 68, Lee Meena (KOR) 71 69 70
211 - Mamiko Higa (JPN) 70 69 72
212 - Paula Creamer (USA) 68 72 72, Dori Carter (USA) 68 72 72, Lizette Salas (USA) 68 72 72, Ryu So Yeon (KOR) 69 70 73
213 - Ayako Uehara (JPN) 69 74 70, Lee-Anne Pace (RSA) 70 71 72, Lin Xiyu (CHN) 72 68 73, Ryann O'Toole (USA) 67 73 73, Mikaela Parmlid (SWE) 69 69 75, Nicole Castrale (USA) 70 67 76
214 - Ji Eun Hee (KOR) 67 75 72, Yoo Sun Young (KOR) 71 71 72, Mariajo Uribe 69 73 72, Pernilla Lindberg (SWE) 68 73 73, Shin Jenny (KOR) 69 71 74, Lee Jee Young (KOR) 70 67 77
215 - Candie Kung (TPE) 72 70 73, Angela Stanford (USA) 69 70 76
216 - Anna Nordqvist (SWE) 70 74 72, Park Inbee (KOR) 69 73 74, Jessica Korda (USA) 72 71 73