Home favourite Kim Bi-O stayed on course for back-to-back OneAsia titles by shooting a five-under-par 67 on Saturday to take a two-stroke lead into the final round of the SK Telecom Open.
But Bi-O's 13-under-par total 203 around the tricky Pinx Golf Club track on the South Korean honeymoon island of Jeju was overshadowed by a blistering course-record 63 from compatriot Hur In-Hoi and a 66 by a teen amateur.
Kim Si-Woo, 16, shared second place with fellow South Koreans Hur and Joo Heung-Choi going into the final round.
Joint overnight leader Park Sang-Hyun was a stroke further back after shooting a 70, while Indonesia's Rory Hie -- who also had a share of the lead at the start of the day -- shot a level 72 to remain at eight under.
Bi-O, a two-time winner on OneAsia after victories in the Nanshan China Masters last year and again last week at the GS Caltex Maekyung Open in Seoul, is currently in second place on the tour's Order of Merit.
He took a grip on the tournament at the par-five ninth when he put his second shot to within six feet and converted for the only eagle there of the day, OneAsia said in a press release.
"I was in that position once," laughed Bi-O when asked what advice he would have for the youngster Kim heading into the final round.
"He mustn't get carried away," said Bi-O. "It is a great learning opportunity for him, but I am sure he will do very well."
Kim Si-woo, clearly nervous in front of the Korean TV cameras after his round, nevertheless talked a brave game.
"I want to be a professional one day, so it is better to learn sooner than later," he said.
The round of the day belonged to Hur In-Hoi, who bettered the course record 64 set last year by a stroke. He started his round with four birdies and an eagle in the first five holes to make the turn in 30, before a more modest 33 on the back nine.
K.J. Choi, with eight PGA tour wins arguably the best player Asia has produced, is 10 shots off the pace after going three under on Saturday.
203 - Kim Bi-O (KOR) 68-68-67
205 - Hur In-Hoi (KOR) 71-71-63, Joo Heung-Chol (KOR) 72-68-65, Kim Si-Woo (KOR) 69-70-66
206 - Park Sang-Hyun (KOR) 71-65-70
208 - Rory Hie (INA) 70-66-72
210 - Lee Sang-Hee (KOR) 72-71-67, Park Jun-Won (KOR) 70-70-70, Mark Brown (NZL) 72-66-72
211 - Kim Gi-Whan (KOR) 72-72-67, Simon Yates (SCO) 71-70-70, Ashley Hall (AUS) 71-70-70, Kim Meen-Whee (KOR) 73-68-70, Mo Joong-Kyung (KOR) 72-67-72