Park Sung-hyun was asked by her mother after the third round of the HSBC Women's World Championship on Saturday if she "felt tired".

The South Korean golfer's Jekyll-and-Hyde performances in the second and third rounds did not go unnoticed by her biggest fan.

The world No. 2 had fired a combined nine birdies on the front nine in those rounds, only to slip up on the back nine with six bogeys and a lone birdie.

In response to her mother's question, the ice-cool Park said: "I told her I still have one more day and just watch my game. Even though I played over par on the back nine in the second and third rounds, I still had the confidence that I could play better on the last day."

True to her word, the 25-year-old fired a scintillating eight-under 64 at Sentosa Golf Club's New Tanjong Course yesterday to overcome a four-shot deficit to world No. 1 Ariya Jutanugarn and win the US$1.5 million (S$2.02 million) tournament with a 15-under 273 total.

Australian Minjee Lee, who took the outright lead at the 13th hole, shot a 69 to finish two strokes behind. Singapore's Amanda Tan, who qualified for the tournament for the third time, finished last with a final-round 77 and a 35-over 323 total.

Through a translator, former world No. 1 Park said: "I never expected my first win of the year would come this quick because I'm usually pretty unstable at the beginning of the season for the last few years. I think the training I had last winter really helped me a lot and made me stronger."

World No. 3 Lee, whose title hopes were scuppered by a bogey on the par-four 14th, said: "I just hit a poor chip shot and that was a mistake. But I feel like I had a really good two weeks and, hopefully, it just sets me up for my career."

Like in her previous rounds, Park got off to a red-hot start yesterday.

She reeled off five birdies through the first seven holes and, despite a bogey at the eighth, the Seoul native did not falter on the home stretch, adding four more birdies on the back nine to claim the US$225,000 winner's cheque.

Park has often been described as an enigma - at 1.72m, she is an average-sized Asian woman, but is an aggressive player whose average driving distance of 269.8 yards ranked sixth on the LPGA Tour last year.

Picking up the sport at age nine after being influenced by her parents, the self-taught golfer has been without a coach since 20.

Park's caddie for two years, 39-year-old Irishman David Jones, called her "a world-class golfer who raises the bar and comes along every 10 or 15 years".

He said: "Her ball-striking is head and shoulders above lots of people. She's long and straight. She hits her irons good and high, and she's a good putter.

"So when you put all those things together, there are not many weaknesses in her game."

The two-time Major champion's (2018 Women's PGA Championship and 2017 US Women's Open) off-the-course demeanour also suits her "Namdalla" nickname which loosely translates as "I am different".

Her androgynous appearance has attracted thousands of female fans who worship her as a rock star. About 30 of them flew in from South Korea to follow her here.

Karen Stupples, who won the 2004 Women's British Open, said: "It borders on hysteria. You have all these women, and the majority of her fans are women, who treat her like the biggest movie star over here. I'm half expecting to see some of them faint."

While Park is known to appreciate and hang out with her fans, she is often emotionless on the course whether she shoots a birdie-filled front nine or a bogey-riddled back nine.

She explained: "Because of the hot weather, I was holding my umbrella. Not only that, but I was also holding it really low so I could just look at the ground and focus more on my playing, which really helped."

With her victory, Park is now projected to regain the top ranking from Ariya, who finished joint-eight (75, 280 total).

"Yes, that is my goal this year," she declared.