BANGKOK: Lexi Thompson secured a comfortable victory at the Honda LGPA tournament in Thailand on Sunday, a move that will push her past Stacy Lewis to become the top-ranked American female golfer.

The 21-year-old, notching up her seventh career win, hardly broke a sweat as she ended the final day with a 4-under par 68 and a total of 268, an unassailable six strokes ahead of runner-up Chun In-Gee from South Korea.

Securing a $240,000 cheque, she became not only the first American to win at the Chonburi course but also the youngest winner there, besting Yani Tseng who triumphed in 2011 at the age of 22.

Thompson began the tournament with a blistering 8-under par 64 before suffering a par-72 wobble on day two.

But she recovered by day three, shooting another magnificent 64 before breezing through the final day.

The win will put her ahead of Lewis, who had held the number one American spot for the last 195 weeks.

Reigning US Women’s Open Champion Chun put on a brave fight in the final round with a birdie on the first three holes, but victory slipped away with four later bogeys and a double bogey.

Fellow American Jessica Korda struck the best final round of the tournament with 64, enough to put her in joint third alongside last year’s tournament winner Amy Yang of South Korea with a total of 275.

Oosthuizen triumphs

South Africa’s Louis Oosthuizen hung on for a one-shot victory and his first win for more than two years, in the European and Asian Tour co-sanctioned Perth International at Lake Karrinyup on Sunday.

A one-under 71 was enough to get the world number 21 home on 16-under 272 over Frenchman Alexander Levy after a closing round containing three birdies and two bogeys.

The 2010 British Open champion led by three shots heading into the final round, but briefly lost the lead to Australian Jason Scrivener.

However, birdies at the seventh and eighth holes steadied Oosthuizen as Scrivener fell away with consecutive bogeys on the ninth and 10th.

Oosthuizen had a three-putt bogey at the final hole as he won his first tournament in Australia and his first since the Volvo Golf Championship in 2014.

Levy fired the equal-lowest round of the day, a six-under 66, to fall just short of forcing a playoff with 15-under. Scrivener holed a 60-foot putt at the last to finish outright third at 14 under.

Another Frenchman Gregory Bourdy, who only made the weekend cut by one stroke, finished tied for fourth place with American Peter Uihlein at 13 under after closing rounds of 65 and 66.

A third Frenchman Romain Wattel finished with a par 72 for 12 under and outright sixth.

Oosthuizen’s 13th career triumph and eighth on the European Tour continues a successful history of South Africans at Lake Karrinyup tournaments, with Ernie Els (2002) and Retief Goosen (2003) claiming Johnnie Walker Classic wins at the course.

Miami.