Rory McIlroy stayed in contention after an up-and-down second round at the Kolon Korea Open.
The former world No 1 followed up his opening round 70 with a two-under par 69 but it proved to be a day of 'what ifs' for the Northern Irishman.
McIlroy started on the 10th with a birdie, and two more followed on his front nine, but he ended it one shot worse off thanks to four bogeys in five holes from the 12th.
Better would follow on the front-nine with birdies at the first and fifth getting him back on track, and he picked up further strokes at the seventh and eighth before finishing with a sloppy dropped shot to lie on three-under.
But that was only two strokes off the lead in tough conditions at the Woo Jeong Hills Country Club course near Cheonan, which was being held by Hong Soon-sang, who carded a second round 68.
McIlroy said: "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.
"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."
South Korean Hong is one stroke clear of three more local players. The trio on four under includes Hyung-tae Kim, whose round of 66 was the best of the day.
McIlroy was a stroke further back along with Ik-jae Yang after the overnight leader could only manage a second round of 72.