Teenage golf star Lydia Ko has split with the only coach she has had since she took up the sport as a 5-year-old.

Guy Wilson, who has worked with the 16-year-old Ko for 11 years, issued a statement saying he was "incredibly disappointed" the partnership is over. Ko has not publicly commented on the decision.

Ko won five professional tournaments — four as an amateur — while coached by Wilson, who said it had "been an honour to help develop Lydia into the No. 4 golfer in the world."

Wilson said "when I first met her the golf clubs were taller than she was and she didn't know the first thing about a driver or a putter but now she has one of the most envied swings in the women's golf world."

Born in South Korea and raised in New Zealand, Ko won the Swinging Skirts World Ladies Masters two weeks ago in Taiwan in her second start as a professional. She won the Women's Canadian Open at 15 last year to become the youngest winner in LPGA Tour history and successfully defended the title this year.