KJ Choi is looking for a second-round improvement after a rollercoaster first day at the inaugural Ballantine's Championship in Korea.

The world No.5, playing in front of his home fans, shot a one-under-par 71 at Pinx Golf Club on Jeju Island on Thursday (March 13).

That left him four shots off the pace being set by Finland's Mikko Ilonen and Australian Tony Carolan.

"The play tended to be a bit slow today, so I struggled with it," said Choi, a seven-time winner on the PGA Tour.

"Also, reading the greens was an issue, so I think there's a lot of practice for me to do."

Choi mixed five birdies with two bogeys and a double bogey at the ?2 million (US$2.9 million) tournament, the first European Tour event to be held in Korea.

The double bogey came on the par-four seventh hole when he ran into an insect problem.

Choi's ball landed near a bunch of ants and there was a long delay while rules officials deliberated what he should do.

"They looked like fire ants," he said. "From what I'm told, on the International Federation of Tours, whenever there is a dangerous situation where it affects play, such as fire ants, then you get a free drop.

"However, I was told there weren't any fire ants in Jeju, so they could not acknowledge it. So I had to take a drop. The drop was pretty good, but it rolled down to a bad spot. I think the ruling could have gone either way."

With large galleries cheering him on, Choi will be looking for a better score when he tees off in Friday's second round.

"This course, you could shoot five or six-under on any day," he said. "The course is in pretty good condition, so all I've got to do is try my best."