By Peter Rutherford

SEOUL (Reuters) - It has been 18 years since Pak Se-ri shed socks and shoes and stepped gingerly into the water to play a daring recovery stroke at the 1998 U.S. Women's Open, a shot that both defined her career and helped change the face of women's golf forever.

Pak's victory over American Jenny Chuasiriporn after a 20-hole playoff in Wisconsin would open up the LPGA Tour to an "Asian invasion" and proved to be a stepping stone for women's golf to reach new markets.

After a retirement ceremony for the 39-year-old trailblazer on Thursday at the co-sanctioned KEB Hana Bank Championship, Pak said it had been difficult to get through the round.

"I reached 18 and I didn't think I could hit the tee shot," she said. "I cried all the way down the 18th. I'd had a lot of victories but that was one of the happiest moments of my career."

Looking back on her 1998 groundbreaking win, Pak said the shot from the water, or rather, making that decision to get into the water and play from an "impossible" position, made her who she is today.

"I know it was impossible but I wanted to try it," she added. "In that moment, without trying it, I don't think I would here as 'Seri Pak'".

It would be difficult to overstate Pak's influence on the women's game.

Comparisons have been made to Tiger Woods and Seve Ballesteros, game changers who brought the sport to new audiences and encouraged a generation to play the game. But for many, Pak's influence is unrivalled.

Korean television deals have become the biggest source of revenue for the LPGA Tour, which makes stops in China, Malaysia, Taiwan, Japan and Singapore this year.

On the playing side, more than a quarter of all LPGA tournaments since Pak's 1998 U.S. Women's Open victory have been won by Korean-born players.

LPGA Commissioner Mike Whan thanked Pak for helping women's golf smash through regional barriers.

"And most importantly, little girls all over the world grew up watching you and saying, 'I want to do that, too,'" he said at a news conference this week.

COUNTRY CAPTIVATED

Some of those she inspired to take up the game, dubbed the "Seri Kids", are here playing in Incheon this week including Ryu So-yeon, Choi Na-yeon, Ji Eun-hee and Chun In-gee, who all followed in Pak's footsteps by winning the U.S. Women's Open.

Seven-times major winner and Olympic champion Park In-bee, missing from the field this week as she continues her recovery from injury, was also on hand at the retirement ceremony.

Park was almost 10-years-old when she stumbled out of bed to see what the commotion was in the TV room as her parents cheered Pak's victory in 1998. She took up golf two days later.

While Pak was locked in an epic battle with Chuasiriporn at Blackwolf Run in 1998, back home in South Korea an entire country sat up in the wee hours of the morning, bleary-eyed but captivated.

Parents woke children from their beds to watch a new national hero emerge, the first female sporting icon in Korea's male-dominated society and one who would help lift the gloom of a financial crisis that had brought the economy to its knees.

Newspapers trumpeted Pak's triumph for days, splashing photo after photo of her holding aloft the U.S. Women's Open trophy.

But it is the image of the barefoot 20-year-old producing a piece of magic from the mud when her title bid was hanging by a thread that still resonates most with South Koreans.

Pak's pale feet and suntanned legs, testament to endless hours spent on the practice range instead of enjoying her youth, became a source of national pride. The media said it embodied Korea's spirit of sacrifice during tough economic times.

As Pak raised aloft the U.S. Women's Open trophy, parents the length and breadth of South Korea looked at their daughters and wondered.

Women's golf would never be the same.

(Editing by)