Big-hitting Kim Dae-hyun and fellow South Korean Kim Dae-sub both snared eagles as each shot a bogey-free 67 to share the par 72 first-round lead at the 29th GS Caltex Maekyung Open, the third leg of the OneAsia season.
Chen Jian and 20-year-old James Su Dong, who topped the leaderboard in the morning after a front nine of 33, finished as the top Chinese players on one-over.
Japan Tour star Kim Kyung-tae, the third-highest ranked South Korean golfer, was also bogey free as he carded a 68 over the mountainous 6,962-yard layout at the Namseoul Country Club on the outskirts of Seoul on Thursday.
Australian Stephen Allan, a former PGA Tour regular, and Japan's Masaya Tomida shot 69 to share fourth place with South Koreans John Huh, Jung Ji-ho, Kang Ji-man, Jang Dong-kyu and veteran Kang Wook-soon. Defending champion Bae Sang-moon shot a 72.
Kim Dae-hyun, fourth on last year's Korean Tour Order of Merit and the longest driver on the circuit, nailed 12 straight pars from hole 10 before he eagled holes four and nine, both par-fives, either side of a birdie on the par-three sixth.
On hole four, the wavy-haired 22-year-old holed a 40-foot eagle putt following a five-iron approach, while on nine he chipped in from just short of the green after using a hybrid for his second shot.
"I was a little bit lucky with the eagles, but overall I'm quite satisfied with my round today as I didn't have any bogeys," said the Daegu resident, who has averaged over 304 yards with his drives on this year's Korean Tour.P "It's not a course where you need to hit long, but a fade helps and I can do that. I feel like I'm playing quite well, so I hope to be in contention at the end of the week."
Kim Dae-sub, second behind Bae on last year's Korean Tour Order of Merit, snared a spectacular eagle of his own on the par-four 10th, where he holed out from 120 yards with his new 48-degree wedge.
"I only had this club fitted on Wednesday, so it was the first time I played with it and it was actually my first shot with it in a tournament," said Kim, a five-time winner on the Korean Tour since turning pro in 2001.
"I hit the ball straight and if the weather stays like this, I'm in with a chance. I was very satisfied with my round as I didn't make any major mistakes."
Kim Kyung-tae, who won the Maekyung Open in 2007 in his rookie season, only picked up one shot on the par-fives, on hole nine. The 23-year-old used accurate iron shots to also birdie par-fours at holes two and 15 and the par-three 17th.
"My iron shots were good today and I only missed two or three greens. I'm happy as I didn't have any bogeys," said Kim, who has played mainly on the Japan Tour for the past two seasons and racked up five runner-up finishes.
"It was a bit difficult on the greens to start with as there was some water on the ground, but it got better as it dried out."
Australians Leigh McKechnie and Michael Wright each shot 70 to lie tied for 11th on two-under with the likes of Han Min-kyu, the first-round leader at last December's Australian PGA Championship.
"It was a tough start as there was a bit of rain and the course was a bit wet, but I was pretty solid overall and only had one bogey, on the par-three 17th," said McKechnie, who won last year's New South Wales Open.
"I've been playing pretty well recently, but haven't really been getting the results. It can be a tough course as it's tough to judge distances on some approach shots and the greens can be hard to read."