Byeong Hun An carded nine birdies and no bogeys for a first-round 61 to grab the outright lead by 3 strokes at the Scottish Open on Thursday.
An, a three-time runner-up who has zero PGA Tour wins in 175 career starts, began play on the 10th and, with five birdies, hit the turn with a 30. His final putt for birdie on No. 9 tied the course record and left him at 9 under, 3 strokes better than Rory McIlroy and Thomas Detry at the Renaissance Club in North Berwick, Scotland.
McIlroy held the lead for part of the first round Thursday, surging to the top of the leaderboard with an eagle on the 630-yard, par-5 No. 3, his 12th hole of the day.
An missed an ace at the 14th and tapped in during a stretch of four consecutive birdies on his opening nine. He grabbed the lead for good with a chip to within 3 feet and the ensuing birdie putt on No. 3 to get to 7 under.