There was a time not too long ago when Cristie Kerr's confidence was tenuous enough that she didn't allow herself to admit she was an elite golfer.

Now, with a new mental approach steering her mind toward the positive and productive, and with results on the course that can't be denied, Kerr not only acknowledges that she's really, really good, but she's aiming to prove it with a rise to No. 1 in the world.

"I feel like I'm just tapping into my potential," she said Sunday after using a birdie on the 15th hole to emerge from a four-way battle and win the Michelob Ultra Open at Kingsmill.

"There's a long time that I didn't, but mental training helps you believe in yourself," she added, referring to her new Zen approach to golf. "I definitely know I'm good."

Good enough to climb from No. 6 in the world to No. 1?

"I think I can," the 31-year-old said. "I mean, I kind of hesitate to say that, but I think I can. I'm not afraid of it any more, which is I think why we're seeing some improvement. ... There's not a whole lot of self-doubt left in there for me."

It showed when she was the only one to make a move down the stretch on Sunday.

It happened as she stood in the fairway on the par-5 15th. Calmed by a few deep breaths as part of her attention to mental training, she used her 3-wood to send the ball soaring toward the green.

"Come on, be right! Come on!" she pleaded as the ball headed toward the green, bounced on and then rolled slightly off the back, leaving her a 45-foot putt from the back fringe.

From there, she made it look easy, two-putting for her second victory at Kingsmill.

"I knew at the time where I stood, and I knew that that was a must," she said of her decision to go for the green on the hole for the first time in the tournament.

Kerr closed with a 1-under 70 to finish at 16-under 268. In-Kyung Kim was second at 14 under after a 71, and Song-Hee Kim (71) and Lindsey Wright (73) tied for third at 13 under.

The victory was Kerr's 12th on tour, and her execution on the critical hole was the difference. Her birdie came just after leader Song-Hee Kim made double bogey at the difficult 16th, and just before In-Kyung Kim and Wright also made bogeys to make the lead two shots.

A testy 6-foot par putt at the par-4 16th and two uneventful pars later, Kerr was collecting the $330,000 winner's check, and begging for the tournament to return next season.

All week long, it had been played under a dark cloud of speculation that Anheuser-Busch, which owns the resort and sponsors the event, will not renew its contract.

"I'll bring a sponsor myself if I have to," she joked in interviews later.

Kerr also moved to the top of the money list with more than $700,000.

In-Kyung Kim, just 20 and seeking her second career victory, finished second when Wright bogeyed the last hole. Kim said weekend three-putts "really killed me in the end."

Wright shared the third-round lead with Kerr.

"Unfortunately, I started a little too aggressive in my putting and made a couple of three-putts earlier on," Wright said. "Otherwise, it might have been different at the turn."

After making just one bogey in the first three rounds, Wright had five on Sunday.

Lorena Ochoa, whose 13-under total after two rounds was a tournament record, started the day five shots back, and a birdie on the first hole hinted that she might make a charge.

But the world's top-ranked player followed with bogeys on three of her next four holes and faded to her second straight 74, leaving her 10th at 7 under. After making the turn at 14 under Saturday, she was 7 over the rest of the way.

Michelle Wie, who started the day 12 shots back, shot a 69 and wound up 11 behind.

Kerr, meanwhile, was steady but not spectacular with two birdies and only one bogey.

"The course played a lot different. It played a lot tougher," Kerr said, citing the still soggy fairways from several days of rain, shifting wind and difficult pin placements.

"I knew the course was playing tough and that I just had to hang in there," she said.