Park had been a dominant star on the Korea LPGA Tour before moving over to the US circuit full-time this season. She earned her LPGA membership after making enough money to place inside the top 40 on the money list in 2016 despite playing in only a few events as a non-member.

Park, who posted four top 10s in 2016, including three at major championships, was already world No. 10 by the time she made the leap to the LPGA Tour. When Ryu reached No. 1 on June 26, Park was No. 8.

Since then, Park has had two wins, including her first major title at the US Women's Open, and recorded five top-10 finishes in nine starts. She now has 8.41 points at the top, 0.03 ahead of Ryu.

The world rankings evaluate a player's performance over a rolling two-year period weighted in favor of the current year, and an extra emphasis is placed on the most recent 13 weeks.

Before becoming a full LPGA member, Park had said her goal was to become the world No. 1 within three years.

"I've accomplished my goal a lot faster than I'd planned, and it does put some pressure on my shoulders," Park said. "But I am also determined to keep trying harder and harder. I think I was able to get this far this fast because I continued to push myself without settling for less."

Park is the fourth South Korean to reach No. 1, after Shin Ji-yai, Park In-bee and Ryu. All three are multiple major champions.

"When I looked at the players who've been at the top before, I always wondered when I'd get there myself and what the view would be like from the top," Park added. "Now that I am at No. 1, I can see just how great those golfers have been."

Park is far from done rewriting record books, as she still has a strong chance of wrapping up a historic rookie season.

Park has already locked down the Rookie of the Year points race. She's also the leading money winner so far with a little over $2.1 million, about $200,000 ahead of Ryu. Park is currently in second place in scoring average with 69.169 strokes per round, right behind the leader Lexi Thompson, who is averaging 69.147 strokes per round. The leading scorer will be awarded the Vare Trophy.

In the Player of the Year points race, Park is trailing Ryu by 162 to 148 with two tournaments left. Players earn 30 points for each victory, 12 points for finishing second and nine points for coming in third, and so forth. But the points are doubled at the season-ending CME Group Tour Championship later this month.

Nancy Lopez in her historic 1978 season remains the only rookie to have swept up the Player of the Year, Rookie of the Year, Vare Trophy and money titles in the same season.

"I have to admit there's a lot riding on the next two tournaments," said Park, who will play this week at Blue Bay LPGA on Hainan Island, China. "I know I have a great opportunity, and I'll try to concentrate on each and every hole." SEOUL, Nov. 7 (Yonhap) --