No way could she have scripted a finish like this.
Facing the scariest shot and the hardest hole on the Old Course — the approach to the 17th, the famous Road Hole — Lewis pictured a low 5-iron that a right-to-left wind would knock down and allow to bounce up the slope toward the flag without going over the back of the green.
"It's one of those shots you see in your head, but you don't really ever pull it off," Lewis said. "And just off the club face, it was perfect."
The ball settled 3 feet away for birdie, the best shot of the tournament, maybe the best of her career.
Then, she wisely used putter from 40 yards short of the 18th green, through the Valley of Sin to 25 feet. Lewis bent over and placed both hands on her knees after making the putt, a birdie-birdie finish that gave another special moment at the home of golf — her second major title.
Lewis saved her best for the final two holes of a marathon finish Sunday and closed with an even-par 72 for a two-shot victory over Na Yeon Choi and Hee Young Park. It ended a record drought for the Americans in the majors — 10 straight, all won by Asian players.
"It's unbelievable," Lewis said. "It all happened so fast at the end. You're afraid for every shot, and all of a sudden you make a couple of birdies and it's over."
It was over early for Inbee Park and her bid to become the first pro golfer to win four straight majors in a single season. Returning to the Old Course in the morning in calm conditions to complete 14 holes of her third round, she couldn't make a putt and lost ground. Park had a 74-78 finish and wound up 14 shots behind.
"I'm really relieved," she said. "I really enjoyed this week, every moment I was here. But it's tough to be in the centre of everything for a week, and I feel exhausted."
The last time Lewis was on these hallowed grounds of golf was in 2008 for the Curtis Cup, her final event as an amateur, and she went 5-0 in her matches to lead the Americans to victory. The love affair continued this week, and her second big win at St. Andrews was even sweeter.
"I love the golf course more than anything. I love the history. I almost felt like I was meant to be here," Lewis said. "I think I was happy being here all week, and I was comfortable. And I think that's a lot of the reason I'm here right now."
Having the silver trophy at her side also required no less than her best golf over 36 holes Sunday.
The wind wasn't as bad as Saturday, when 40 mph gusts suspended play and forced 20 players go to 36 holes Sunday. But it was strong enough in the afternoon that Lewis was the only player at par or better from the last 21 groups that teed off.
Choi had a three-shot lead with six holes to play until she had a pair of three-putt bogeys from 80 feet. Her hybrid was too strong on the 17th and hung up on the collar of rough at the back of the green. She missed a 6-foot par putt that ended her chances, and she closed with a 73.
Choi saw that Lewis had posted at 8-under 280, she just didn't know how she got there. And she couldn't believe it when she heard.
"She got birdie on 17 and 18? That's huge, especially this golf course," Choi said. "I feel like I missed a couple putts out there, but still, she's playing well. She's playing better than me. I think that's why she won. I think I have to accept that."
Hee Young Park, one of four players who shared the lead at some point in the final round, had three straight bogeys on the back nine and shot 73. Morgan Pressel had the 54-hole lead after a 71 in the wind-delayed third round that was played Sunday morning. Pressel was one shot behind until a double bogey on No. 12, and she never caught up. Pressel shot 76 and tied for fourth with Suzann Pettersen (74).
The consolation for Pressel was earning the last spot available from the world ranking to make her third straight Solheim Cup team.
It was the second time the Women's British Open was played at St. Andrews, and Lewis provided another quality winner. Lorena Ochoa won in 2007.
Lewis last year became the first American since Beth Daniel in 1994 to win LPGA player of the year, which is based on a points system. Then, she won twice early this season to reach No. 1 in the world. That lasted only until Park won the first major and kept right on going.
Sunday was another stage for Lewis to show her grit.
She was diagnosed with scoliosis when she was 11, so severe that she wore a back brace for 18 hours every day from age 11 until she got out of high school, and then had to have surgery when that didn't correct the curvature in her spine.
She went on to win an NCAA title at Arkansas, star at St. Andrews in the Curtis Cup and then take the 54-hole lead in her first U.S. Women's Open as a pro. Lewis won the Kraft Nabisco in 2011, the last American major champion in women's golf until her remarkable performance Sunday.
Nothing was more impressive than her 5-iron on the 17th, one of the toughest par 4s in golf that starts with a blind tee shot over the corner of the Old Course Hotel. Lewis drilled it in the middle of the fairway, and couldn't remember how far she had for her second shot. With the wind, it didn't matter. This is the kind of shot that must be felt, and her 5-iron was hit with the right trajectory and line to catch the slopes perfectly and feed toward the hole.
"That might be one of the best of my career," Lewis said.
Oddly enough, it was Lewis who said she would like to play the role of spoiler at St. Andrews to stop Inbee Park's bid for history. With the trophy at her side, Lewis marveled at what Park had accomplished this year.
"I don't know if you'll ever see three in a row again," Lewis said. "That's pretty incredible."
Lewis now is at one in a row, headed to the Solheim Cup in two weeks on a high, and then to France in September for the fifth and final LPGA Tour major at the Evian Championship. She didn't mind losing the No. 1 ranking because Park earned it. Lewis looked strong enough Sunday at St. Andrews to believe she can get it back one day.