Choi blitzes course record to lead Aussie Open golf
South Korea's Chella Choi pictured during round three of the Marathon Classic in Sylvania, Ohio on July 20, 2013 - by Hunter Martin
Choi, who is yet to win on the US LPGA Tour, carved up the back nine with birdies on 12, 14, 15, 16 and 17, and an eagle on 18, to lower the Victoria Golf Club women's record of 64 set on Friday by Caroline Hedwall.
Perth teenager Lee, runner-up to Tiger Woods' niece Cheyenne at last week's Australian Ladies Masters, shot a 68 to match Choi's aggregate score of 13-under-par 203.
However, the joint leaders will be acutely aware of New Zealand sensation Lydia Ko, 16, who was lurking two shots back in third place after scoring 69 on day three.
Norwegian world number two Suzann Pettersen, who will reach the top ranking if she wins or finishes second, providing she is not tied with more than one other player, was three shots adrift in fourth.
The day's events left the tournament tantalisingly poised heading into the final round with so much at stake for all four leading players.
Choi, the world number 28, is seeking her first win after turning professional in 2008, while Lee could announce herself to the world by becoming the tournament's first amateur winner.
And South Korean-born Ko, already fourth in the world after winning twice on tour as an amateur, is within reach of her first LPGA victory since turning professional late last year.
Overnight leader Hedwall slipped to four shots back and a share of fourth after returning two-over 74, while defending champion Jessica Korda, who won last month's season-opener in the Bahamas, was five adrift.
Cheyenne Woods, 23, carded 71 for a share of 23rd and has little realistic chance of recording back-to-back wins after last week's victory on the Gold Coast, which was the biggest of her career so far.