SEOUL: Defending champion Moon Kyong-Jun from South Korea on Friday secured the halfway lead in the GS Caltex Maekyung Open in Seoul. Moon shot a four-under-par 68 at Namseoul Country Club to lead by two at the OneAsia event after the second round, with a nine-under 135. His countryman Park Sang-Hyun fired a 70 for 137. Australian Michael Sim is in sole possession of third place after coming in with a 69, while South Korea's Lee Soo-Min carded 69 and is in fourth place with 139. Five off the lead were South Koreans Kim Bio and Kim Hyung-Sung along with compatriot Kim Kyung-Tae. Kyung-Tae shot a 69 while Bio returned a 71 and Hyung-Sung carded a 73.