Rory McIlroy is two shots off the lead after the second round of the Kolon Korea Open at the Woo Jeong Hills Country Club course near Cheonan.
The world number six shot a 69 that could have been even better had he not bogeyed on the ninth, his last.
The four players ahead of McIlroy are all South Korean, with Hong Soon-sang carding a bogey-free three-under-par 68 to top the leaderboard.
He is on five-under overall, one stroke ahead of compatriots Kang Sung-hoon, Kim Hyung-tae and Hwang In-choon, while tied fifth with McIlroy are two more home favourites - Yu Gyoung-yoon and first-round leader Jang Ik-jae.
McIlroy, who is playing his first tournament after a month-long break, had a topsy-turvy opening nine, with two birdies and a bogey coming in his first four holes and him then dropping a shot on three holes in a row from 14 to 16.
The former world number one bounced back to score five birdies in the next 10 holes.
Giving his reflections, McIlroy told oneasia.asia: "Pretty good so far.
"There was a few sloppy shots, or sloppily played holes. I made the bogeys on the back nine (his first nine) which wasn't great but most of the other stuff was actually pretty solid. I hit some good shots and made some good birdies so it was good.
"I'm driving the ball very well and for the most part my iron play is pretty good, but I definitely missed a few opportunities out there. I definitely could have been a few shots better, but I'm in a good position going into the weekend and that's all you can ask for.
"After that stretch (of bogeys) today on the back nine I turned it around and played the last 10 holes in four under, so it was a pretty good effort. I was a little disappointed to bogey the last there, but it was good for the most part."
Asked about his strategy for day three, the 24-year-old added: "Just to keep playing the way I am, stay patient. I don't need to go out there and be overly aggressive, but I just want to get myself into a good position for Sunday if possible."