South Korean youngster Noh Seung-yul overcame an injured ankle to hit a bogey-free round of 63 to trail U.S. Open champion Rory McIlroy by two strokes at the halfway stage of the $5 million Shanghai Masters Friday.

The 20-year-old Noh hit nine birdies to set a course record on the Lake Malaren course in Shanghai, designed by Jack Nicklaus, for a two day total of 135.

I have hurt my ankle, not been able to practice too much and also not able to swing as hard as I would like. I just decided to be careful with how I played, Noh told reporters after the second round.

I putted well and chose good options which obviously helped my score, I think the course suits me as well.

McIlroy struggled on the front nine, bogeying the fourth hole and then dropping two shots on the ninth but he recovered with four birdies on the back nine for a three-under 69.

I liked the birdie on 18, and had a good back nine. To shoot four birdies kept me going after the double bogey on the ninth, McIlroy said.

On the ninth I hit my tee shot into the water and tried to make par to recover but ended up with a double.

I know my 64 from yesterday has already been replaced by Noh and his 63, but will try hard to keep hitting the birdies needed to win this weekend.

American Anthony Kim and South Africa Louis Oosthuizen were three strokes behind the leader at joint third while Ireland's Padraig Harrington and American Hunter Mahan were a shot further behind at tied fifth.

Thirty players are fighting for the first prize of $2 million in the inaugural event, which is not sanctioned by a major tour and does not have world-ranking points.

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