SEOUL  - Kim Bi-O showed a maturity that belied his youth Saturday to shoot a five-under-par 67 and take a two shot lead into the final round of the GS Caltex Maekyung Open Golf Championship.

The 21-year-old from South Korea sits on an 11-under-par total of 205 after a scintillating third round display on the hilly 6,964 yard (6,368 metre) Namseoul Country Club course in Seoul.

Bi-O, who won the Nanshan China Masters OneAsia event last year, dropped only one shot all day — a missed four-foot putt on the last giving the chasing pack a hope going into Sunday’s final round.

“I tried really hard to concentrate out there and it went well all day until that bogey on the last,” Bi-o said. “I just want to go out there tomorrow and do the same thing,” he added in comments released by the organisers.

Bi-O scored three birdies either side of the turn to leave him best placed to win the third event of the 2012 OneAsia circuit.

The par-five 14th was pivotal when overnight leader Park Sang-Hyun bogeyed after twice hooking into the woods that line the course.

A birdie by Bi-O meant a two-shot swing and a lead he never looked like relinquishing.

Park, 29, lies alone in second place, with Hwang In-Choon, 37, and Choi Ho-Sung a shot further back at eight-under after both scoring 68s on Saturday.

The OneAsia tour has 14 events this year with a total purse of over $16 million.

Leading scores after the third round (par 72):

205 - Kim Bi-O (KOR) 69-69-67

207 - Park Sang-Hyun (KOR) 68-69-70

208 - Hwang In-Choon (KOR) 69-71-68, Choi Ho-Sung (KOR) 70-70-68

211 - Hu Mu (CHN) 68-75-68, Lee Sang-Hee (KOR) 70-72-69, Lucas Lee (BRA) 71-70-70, Kang Kyung-Nam (KOR) 68-70-73

212 - Park Jun-Won (KOR) 70-74-68, Ryu Hyun-Woo (KOR) 73-71-68, Jason Kang (USA) 70-72-70, Kim Kyung-Tae (KOR) 70-72-70, Song Young Han (KOR) 71-70-71, Kwim Wi-Joong (KOR) 71-70-71, Lee Seong-Ho (KOR) 70-69-73