World number one Park In-Bee was the only player to break par in the third round of the US Women's Open on Saturday, stretching her lead to four strokes over compatriot I.K. Kim.

Park, seeking a slice of LPGA history as she chases a third major title in as many major championships this season, birdied the 18th hole at Sebonack Golf Club to cap a one-under par 71 that gave her a 10-under total of 206.

"I'm just going to try to do the same thing that I did for the last three days," Park said of her chance on Sunday to become the first LPGA player to win the first three majors of a season in which there were more than three.

"It will be a big day, but it's just a round of golf, and I just try not to think about it so much."

Kim, who trailed Park by two going into the third round, posted a one-over

73 for 210.

England's Jodi Ewart Shadoff carded a two-over 74 and had sole possession of third place on three-under 213.

American Angela Stanford (74) and 2011 champion Ryu So-Yeon of South Korea

(73) were at one-under 215 through 54 holes.

"I think I played very good today, especially after the three bogeys," Park said. "I came back very strong. I probably putted the best out of all the three days."

Park said the windy conditions and some testing pin positions made for a difficult day -- typical of a US Open.

"It was a very grinding day," she said.

The second round was completed earlier Saturday after being suspended due to fog on Friday.

Park had just managed to complete her second round on Friday evening. She got off to a steady start in the third round, with pars at her first eight holes before her first birdie of the day at the ninth, where she hit a wedge to three feet and made the putt.

Park's pursuit of a slice of LPGA history was looking a little shaky, however, when she bogeyed three straight holes starting at the 11th.

But the South Korean superstar responded with birdies at 14 and 15, before finishing her round with a flourish.

"Thirteen was a little bit disappointing, and I think that actually got me going after that bogey," she said. "That bogey was a bad bogey so I really got my concentration going after that."

She drained a 30-footer for birdie at 14 and a 15-footer at 15. She blasted out of a bunker to about 10 feet at the last and made that.

Park, whose five titles in 2013 include major triumphs at the Kraft Nabisco Championship and the LPGA Championship, is trying to become the first woman to win the first three major championships in a year in which more than three tournaments were designated as majors.

Babe Zaharias won all three majors in 1950, comprising the Titleholders Championship, Women's Western Open and the US Women's Open.

In 1961 Mickey Wright won the LPGA Championship US Women's Open and Titleholders but was third in the Western Open, designated a major that year.

In 1986, Pat Bradley won the Kraft Nabisco, LPGA Championship and du Maurier Classic but missed out at the US Women's Open.

This year, the LPGA has designated five tournaments as majors: the Kraft Nabisco, LPGA Championship, US Women's Open, Women's British Open and the Evian Championship in France.

Park said she couldn't afford to be complacent on Sunday.

"Four shots, it could be nothing around this golf course," she said. "I just have to keep pushing myself to make pars." (AFP)