Lydia Ko said she had enjoyed a "Cinderella" story after ending an eight-year wait for a major title by winning the Women's British Open at St. Andrews on Sunday, just a fortnight after her Olympic gold medal triumph in Paris.

The New Zealander finished in champion style with a superb birdie on the 18th hole of a windswept Old Course to complete a round of three-under-par 69 and claim her third major title with a tournament total of seven under.

"It is surreal," Ko said. "Winning the gold medal in Paris a few weeks ago was almost too good to be true. Heading into the weekend I thought 'how is it possible for me to win the Open?'.

Ko entered the final day three shots back of third-round leader Jiyai Shin, a two-time Women's Open champion.

Shin was one of four women tied for second, with China's Ruoning Yin, Nelly Korda and Lilia Vu – each of them former major winners who have been ranked No. 1 in the world.

"This is almost too good to be true," she added. "Out of all the major championships, this was the one I had the least amount of confidence in."

Victory gave Ko, 27, her first major since she won the 2016 Chevron Championship. (AFP/Reuters)