Matthew Wolff dropped two shots in his final three holes but still held the lead at the half-way point of the World Wide Technology Championship in Mexico.
The American followed up his opening round of 61 with a 68 on Friday for 13-under in the tournament, two shots ahead of compatriot Scottie Scheffler.
Wolff started well and had three birdies across his first five holes, then dropped a shot on the sixth and cancelled that out on the seventh to reach the turn in three under.
Two birdies and two bogeys coming home meant he stayed at three under for Friday, while Scheffler strung together five birdies and had two more to move 18 places up the leaderboard.
Carlos Ortiz and Victor Hovland are a shot further back and tied for third, the Norwegian recovering from a double bogey on the par-four first hole.
Martin Laird leads the British contingent and is tied for 15th after signing for a 66 to go eight under while Danny Willett and Tyrrell Hatton are six under and tied for 28th.
Between them, tied for 22nd, is Séamus Power who followed up his opening 68 with a 67. The Waterford man dropped just the one shot during his round with a bogey at the par-four third, as birdies came at two, five, seven, 13 and 17.
Power will be the sole Irish representative heading into the weekend as both Shane Lowry and Graeme McDowell missed the cut. A round of two under was not enough for Lowry, who at one point was inside the cut line only to drop shots at the 14th and 16th respectively.
McDowell finished one shot further back on one under overall after a level par second round of 71.
Second round scores & totals in the USPGA Tour World Wide Technology Championship at El Camaleon Golf Club, Mexico:
(USA unless stated, Par 71):
129 Matthew Wolff 61 68
131 Scottie Scheffler 67 64
132 Viktor Hovland (Nor) 67 65, Carlos Ortiz (Mex) 67 65
133 Sergio Garcia (Spa) 64 69, Talor Gooch 64 69, Bill Haas 65 68, Billy Horschel 64 69, Anirban Lahiri (Ind) 67 66, Ryan Palmer 69 64, J. J. Spaun 65 68, Justin Thomas 68 65, Michael Thompson 68 65, Aaron Wise 63 70
134 Doug Ghim 69 65, James Hahn 67 67, Russell Henley 65 69, Garrick Higgo (Rsa) 71 63, Matt Kuchar 68 66, Martin Laird (Sco) 68 66, Andrew Landry 66 68
135 Thomas Detry (Bel) 67 68, Charles Howell III 69 66, John Huh 66 69, Denny McCarthy 67 68, Joaquin Niemann (Chi) 69 66, Seamus Power (Irl) 68 67
136 Abraham Ancer (Mex) 68 68, Joel Dahmen 65 71, Roberto Diaz (Mex) 71 65, Tony Finau 67 69, Tyrrell Hatton (Eng) 70 66, Adam Long 66 70, Alexander Noren (Swe) 69 67, Henrik Norlander (Swe) 70 66, Andrew Putnam 68 68, Doc Redman 70 66, Nick Taylor (Can) 67 69, Brendon Todd 67 69, Danny Willett (Eng) 68 68
137 Christiaan Bezuidenhout (Rsa) 69 68, Tyler Duncan 67 70, Matthew Fitzpatrick (Eng) 68 69, Adam Hadwin (Can) 69 68, Chris Kirk 64 73, Patton Kizzire 68 69, Danny Lee (Nzl) 68 69, Maverick McNealy 68 69, Keith Mitchell 68 69, Chengtsung Pan (Tai) 69 68, Scott Piercy 69 68, Justin Rose (Eng) 67 70, Brandt Snedeker 66 71, Brendan Steele 70 67, Sepp Straka (Aut) 66 71, Adam Svensson (Can) 72 65, Kevin Tway 68 69
138 Keegan Bradley 71 67, Rickie Fowler 66 72, Tom Hoge 72 66, Troy Merritt 68 70, Aaron Rai (Eng) 67 71, Chez Reavie 66 72, Patrick Reed 73 65, Charl Schwartzel (Rsa) 69 69, Greyson Sigg 69 69, Brian Stuard 69 69, Hudson Swafford 68 70, Vincent Whaley 70 68, Andrew Novak 66 72
The following players missed the cut:
139 Charley Hoffman 71 68, Sung-Hoon Kang (Kor) 68 71, Russell Knox (Sco) 69 70, Hank Lebioda 73 66, Luke List 69 70, Ian Poulter (Eng) 66 73, Davis Riley 70 69, Rory Sabbatini (Svk) 68 71, Roger Sloan (Can) 69 70, Harold Varner III 71 68, Jhonattan Vegas (Ven) 71 68, Camilo Villegas (Col) 69 70, Gary Woodland 67 72
140 Luke Donald (Eng) 73 67, Brice Garnett 71 69, Emiliano Grillo (Arg) 67 73, Kramer Hickok 68 72, Matt Jones (Aus) 70 70, Nate Lashley 68 72, Shane Lowry (Irl) 71 69, Ryan Moore 68 72, Trey Mullinax 69 71, Pat Perez 72 68, J. T. Poston 71 69, Sam Ryder 73 67, Kyle Stanley 74 66, Kevin Streelman 70 70, Will Zalatoris 71 69
141 Dylan Frittelli (Rsa) 71 70, Brian Gay 75 66, Stephan Jaeger (Ger) 67 74, Graeme McDowell (NIrl) 70 71, Henrik Stenson (Swe) 69 72, Martin Trainer 72 69, Cameron Tringale 70 71, Nick Watney 72 69, Braden Thornberry 70 71
142 Juan Carlos Benitez (Mex) 74 68, Jonas Blixt (Swe) 72 70, Zach Johnson 73 69, Brooks Koepka 71 71, Patrick Rodgers 70 72, Richy Werenski 73 69
143 JD Fernandez (Mex) 69 74, Brian Harman 73 70, Lucas Herbert (Aus) 75 68, Guido Migliozzi (Ita) 69 74, Francesco Molinari (Ita) 72 71, Adam Schenk 73 70, Jimmy Walker 72 71
144 Peter Malnati 73 71, Taylor Pendrith (Can) 76 68, Scott Stallings 75 69
145 Curtis Thompson 75 70
146 Joseph Bramlett 69 77, Eugenio Lopez-Chacarra (Spa) 73 73, Willie Mack III 73 73, David Lipsky 77 69, Camilo Aguado (Col) 74 72
148 Guillermo Mito Pereira (Chi) 70 78
152 Samuel Del Val (Spa) 76 76
