Rory McIlroy slipped ten shots behind leader Rickie Fowler as he only managed a third round 73 at the Kolon Korea Open.
The young Ryder Cup stars from opposite sides of the Atlantic both held a share of the overnight lead, but while US Open Champion McIlroy had four bogeys, four birdies and a double bogey, American Fowler carded eight unanswered birdies in a 63.
At 13 under Fowler leads by four from former US PGA Championship winner Y E Yang, with Kim Meen-whee in third on seven under.
“I had a good round and I can’t complain with a 63,” said 22 year old Fowler.
“Going into the round I wanted to drive the ball well and make some putts, and I was able to do that and that puts me in a good position. My goals were to drive well and putt well, but my overall game was also good.
“I think I can win,” he added. “I feel good about my game and I’m in a great position, which is right where I wanted to be coming into the week.”
Yang carded a third round 67 and the 39 year old defending champion is confident of making a final round challenge.
“Rickie and I had a good battle at the top of the leaderboard and I am satisfied with the round,” he said.
“I made bogeys on the par fours after I hit bad tee shots, but if I can drive well in the final round, I have a chance to get a low score.”
World Number Three McIlroy was left to rue a combination of poor putting and a drive out of bounds.
“I had a good finish, but it was not my best day,” he said. “I played quite nicely over the first few holes, but the pin positions were very tricky. I was two under through eight holes and I felt pretty good, but I missed a little putt on nine which threw me a little.
“I played ten and 11 pretty well, but I hit a tee shot on 12 which I have not hit that wide all week. And after I hit my first ball out of bounds, I then hit my second in the rough and as I was taking a practice swing I hit another ball which I didn’t see and at first the rules official said that I had played a wrong ball.
“I had no intention of hitting it, but I got it up and down with the other ball and thought I had made seven, but the rules official then said it was OK and I actually made five. That got into my head a little and I lost it a bit on the back nine and I got on a bit of a bad run, but I then played the final two holes a lot better after two good drives.”