Miyazato climbed to the summit on Sunday, shooting a 7-under 64 to win the $1.5 million ShopRite LPGA Classic by two strokes over M.J. Hur of South Korea on Seaview's  Bay Course, not far from the Atlantic City casino resort.
It was the fourth win in nine events this year for Miyazato, who is finally living up to the expectations thrust on her in 2006 when she made the move from Japan to the US LPGA Tour. The 25-year-old now has five wins in the last two seasons, and she is starting to dominate in a way akin to Ochoa and Annika Sorenstam.
"When I started playing in the States, that's when I really started thinking about being No. 1," Miyazato said after giving herself a belated (Saturday) birthday present.
«That became a dream of mine, especially watching Annika (Sorenstam) and Lorena play. Now that I am No. 1, I still can't believe it, but I do feel very comfortable with it." The Rolex women's rankings won't be announced until Monday, but the US LPGA said Miyazato will be No. 1.
"Ai is not only one of the greatest golfers out here, but she is such a good person," said Paula Creamer, who threatened for two rounds and faded (71) to seventh in her first tournament since surgery on her left thumb in March.
"Japan should be so proud because she represents her country to the highest level," Creamer said. "And you know, I know Ai really well. She's a good friend of mine, so to see her succeed, and when she went through that rough patch a couple years ago, it's amazing how she's totally overcome all of that." Miyazato was machinelike in the final round of the 54-hole tournament. Trailing Hur by two shots, she had a piece of the lead after making a 15-foot birdie at No. 2 and a tap-in on the par-5 third hole. A 3-foot birdie on No. 9 gave her sole possession of the lead and she opened daylight with a 15-footer on No. 10 and a 30-footer for birdie on the 14th hole.
The birdie on 10 came after she played out of a fairway bunker.
"I believe in myself and the game and no matter what the situation is or the pressure is I feel like I can play my game," said Miyazato, who had seven birdies and no bogeys over the final 18 holes.
While the winning margin was two shots, it was really never that close. Hur, the second-round leader, had to birdie the final three holes just to get second place.
Even when the 20-year-old Hur, who was playing in the group behind Miyazato, drew to within two shots with birdies at Nos. 16 and 17, the Japanese star responded. She hit her third shot within 10 feet and made the birdie.
Miyazato had a final total of 16-under 197 to earn a winner's check of $225,000, pushing her earnings this year to $830,238.
Her earlier wins this year were in Thailand, Singapore and Mexico. Her first US LPGA win came last year in France.
Suzann Pettersen of Norway, South Korea's Hee-Won Han and Katherine Hull of Australia shared fourth place at 11 under, one shot ahead of Creamer.
Miyazato will replace Jiyai Shin of South Korea atop the rankings. Shin has missed the last two tournaments after undergoing an appendectomy. She hopes to return to the tour in next week's LPGA Championship in Rochester, New York.
Shin took over the top spot after Ochoa retired earlier this year to focus on starting a family.