A surge of birdies on the front nine was enough to propel Scotland's Russell Knox to the top of the leaderboard following the opening round of the Mayakoba Golf Classic in Mexico.
Starting on the back nine, Knox opened his tournament steadily with pars on the 10th, 11th and 12th before roaring into life with birdies on five of the next six holes.
He then added two more birdies on the front nine, with a bogey on the second the only blemish in his stellar round of six-under 65.
Knox heads into the weekend one shot clear of Joaquin Niemann, Emiliano Grillo and Tom Hoge, with the top 12 players separated by just two strokes.
Graeme McDowell, the only Irish golfer in the field, carded a one-under par round of 72.
