Kang Ji-man has taken the sole lead of the GS Caltex Maekyung Open Golf Championship after a five-under-par opening round on Thursday. Australia&aposs Mitchell Brown is four strokes adrift of Kang on one under after he signed off for a first-round 71. Amateur Song Tae-hoon is one shot behind Kang in second place after a four-under-par 68 at the Nam Seoul Country Club, while defending champion Kim Kyung-tae is a shot further back. Kim carded an opening round of 69 and is two shots off the lead alongside Park Sung-kook, Lee Jin-won and youngster Noh Seung-yul. Six players are tied on two under, while the only non-Koreans in the top 20 along with Brown are Japan&aposs Yoshinobu Tsukada and Chris Riley, of the United States, who are in a group of nine tied on one under. Kang, whose only professional victory was in the 2006 Shinhan Donghae Open when he finished ahead of KJ Choi and Michael Campbell, started on the back nine and was three under after nine holes. He carded a further three birdies on the incoming nine to take a one-stroke overnight advantage. Song made a steady start to take sole possession of second place, while Noh&aposs bid for a title before his 17th birthday remained firmly on track. The 16-year-old, who turns 17 on May 29 and has recorded two runner-up finishes and one top-10 place this year, carded four birdies against one bogey. England&aposs Chris Rodgers and Malaysia&aposs Iain Steel were among a group of 13 on level par. Round One of the GS Caltex Maekyung Open, Seoul -5: Kang Ji-man 67 -4: Song Tae-hoon 68 -3: Park Sung-kook 69, Lee Jin-won 69, Noh Seung-yul 69, Kim Kyung-tae 69, -2: Jun Tae-hyun 70, Kim Do-hoon III 70, Young Nam 70, Kong Young-joon 70, Park Do-kyu 70, Kim Dae-hyun 70 -1: Yoshinobu Tsukada 71, Lee Boo-young 71, Cho Byung-min 71, Choi Hyuk-jae 71, Lee In-woo 71, Mitchell Brown (Australia) 71, Hwang In-choon 71, Bae Sang-moon 71, Chris Riley 71 Also: Even: Eddie Lee (New Zealand) 72 +1: Ashley Hall (Australia) 73, Michael Wright (Australia) 73, Nevin Basic (Australia) 73, +2: Adam Groom (Australia) 74, +4: Tony Carolan (Australia) 76, Stephen Scahill (New Zealand) 76, Gavin Flint (Australia) 76, Scott Hend (Australia) 76 +5: Uhno Park (Australia) 77, Richard Lee (New Zealand) 77 +6: Gary Simpson (Australia) 78, Richard Moir (Australia) 78, Jason King (Australia) 79, Andrew Dodt (Australia) 82 +10: Kane Webber (Australia) 82 +11: David Gleeson (Australia) 83