WAShINGTON - US star Lexi Thompson won her eighth career LPGA title Sunday, firing a six-under par 65 to capture the Kingsmill Championship by five strokes for her first victory of 2017.

Thompson had appeared set to win a major title last month at the ANA Inspiration before a television viewer using slo-motion replay discovered a violation, resulting in a day-late application of a four-stroke punishment that led to her eventual loss in a playoff.

That prompted a rule change too late to help Thompson, who fought through the heartache and admitted Sunday's triumph at Williamsburg, Virginia, carried extra special meaning because of how she lost last month at Rancho Mirage, California. "Oh it really does," Thompson said. "It has really been tough the past few months. I've been working so hard for this."

Thompson sky dived to her pro-am tee time on Wednesday and was flying high all week, finishing 72 holes in a tournament record 20-under par 264 to defeat South Korean Chun In-Gee by five strokes for her first Kingsmill crown. "I just felt really confident coming into the week," Thompson said. "I knew I had put in the work."

Supportive spectators helped her set aside the sting of her earlier setback. "It truly means the world, just to have this amount of people at this event, cheering me on, giving me high fives," she said. "It means a lot." Thompson matched the lowest final round of her career and her first and second rounds with a 65, making this her sixth career event with four rounds in the 60s.

Thompson made only two bogeys on the week, both at the par-3 17th. She began the last round with a three-stroke edge and went bogey-free, birdies to open and close the front nine plus at the par-5 third and 15 and the par-4 12th and 14th.

American Angela Stanford was third on 273, one stroke ahead of compatriot Danielle Kang with South Korea's Kim Sei-Young and Spain's Carlota Ciganda sharing fifth on 275. World number one Lydia Ko of New Zealand held onto her spot atop the rankings by sharing 10th on 277 despite a final-round 73.

Second-ranked Ryu So-Yeon of South Korea also shared 10th while the other rival who could have overtaken Ko, Thailand's Ariya Jutanugarn, shared 19th on 280. Ariya needed at least a top-seven effort and a poor showing by Ko to claim number one while Ryu would have needed a fourth-place finish to dethrone the Kiwi after her top-10 effort.