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 is down the leaderboard in a share of 70th place, alongside Luke Donald, after he shot a one over par opening round of 72.
Collated first round scores in the USPGA Tour Mayakoba Golf Classic (USA unless stated, par 71):
65 Russell Knox (Sco)
66 Emiliano Grillo (Arg), Joaquin Niemann (Chi), Tom Hoge
67 Carlos Ortiz (Mex), Aaron Wise, Viktor Hovland (Nor), Nate Lashley, Michael Gligic (Can), Tony Finau, Brendon Todd, Akshay Bhatia
68 Joel Dahmen, Hunter Mahan, Pat Perez, Kyle Stanley, Harry Higgs, Christopher Baker, Bo Hoag
69 Brandon Hagy, Daniel Berger, Chase Seiffert, Ryan Brehm, Steve Stricker, Chris Kirk, Rory Sabbatini (Svk), Jason Dufner, Kyoung-hoon Lee (Kor), (a) Austin Eckroat, Andy Ogletree, Harris English, Kevin Streelman, Keegan Bradley, Ryan Armour, Jhonattan Vegas (Ven)
70 Satoshi Kodaira (Jpn), Harold Varner III, Austin Cook, Kelly Kraft, J.J. Spaun, Patrick Rodgers, Billy Horschel, Kyung Ju Choi (Kor), Rickie Fowler, Sung Kang (Kor), Brian Harman, Scott Piercy, Maverick McNealy, Adam Long, Keith Mitchell, Camilo Villegas (Col), John Huh, Tyler Duncan, Troy Merritt, Michael Gellerman
71 Luke List, Henrik Norlander (Swe), Vincent Whaley, Mark Hubbard, Lucas Glover, Branden Grace (Rsa), Matt Every, Doug Ghim, Brooks Koepka, Brendan Steele, Rob Oppenheim, Hank Lebioda, (a) Quade Cummins, Corey Conners (Can)
72 Rafael Campos (Dom), Brian Stuard, Nick Watney, Charley Hoffman, Andrew Putnam, Will Zalatoris, Byeong-Hun An (Kor), Gary Woodland, Adam Hadwin (Can), Bronson Burgoon, Charles Howell III, Justin Thomas, Xinjun Zhang (Chn), Russell Henley, Graeme McDowell (NIrl), Sam Ryder, Cameron Percy (Aus), Kristoffer Ventura (Nor), Aaron Baddeley (Aus), Abraham Ancer (Mex), Ben Taylor (Eng), Patton Kizzire, Luke Donald (Eng)
73 Armando Favela, Sepp Straka (Aut), Tim Wilkinson (Nzl), Drew Nesbitt (Can), Kiradech Aphibarnrat (Tha), Max Homa, Scott Harrington, Michael Kim, Sebastian Munoz (Col), Johnson Wagner, D.J. Trahan
74 Denny McCarthy, Robby Shelton, Roberto Diaz (Mex), Marc Leishman (Aus), Bo Van Pelt, Chesson Hadley, Rafael Cabrera-Bello (Spa), Brice Garnett
75 D.A. Points, Adam Schenk, Roger Sloan (Can), Joseph Bramlett, Aaron Terrazas (Mex), Will GordonMark Anderson
76 Alex Noren (Swe), Vaughn Taylor, Patrick Cover, Beau Hossler, Santiago Tarrio Ben (Spa), Fabian Gomez (Arg)
77 Sebastian Cappelen (Den), Kevin Stadler, Rhein Gibson (Aus)
78 Peter Malnati, Wesley Bryan, Ollie Schniederjans, Chez Reavie
80 Isidro Benitez (Mex)