Palm Harbour - Zimbabwe's Brendon de Jonge fired four birdies in a two-under 69 on Friday to grab a one-shot lead over the chasing pack in the PGA Tour's $5.9 million Valspar Championship.
Going after his first PGA Tour title, de Jonge's 36-hole total of six-under 136 saw him heading into the crucial weekend narrowly ahead of a clutch of more celebrated players.
World number three Henrik Stenson of Sweden and rising US star Jordan Spieth were among a group of five players sharing second on 137.
Spieth had seven birdies in a four-under 67, rolling in a 17-foot birdie putt from off the green at the 18th. Stenson had an eagle and a birdie in his 70.
Ryan Moore (68), Derek Ernst (70) and Kevin Streelman (69) were the rest in the pack.
De Jonge teed off early at the 10th on Innisbrook's Copperhead course and had the luxury of playing his first nine holes before the wind picked up.
"Got a little bit more defensive," he said of adjusting once the conditions changed, although he still grabbed birdies at two of his final three holes - the par-four seventh and the par-four ninth.
"I made a 50-footer over there on number seven and number nine was playing straight downwind, so you could get pretty aggressive there," he said.
"I made a soft bogey on number six after driving it perfectly."
De Jonge said his tee shot at the seventh was "terrible" but he was lucky enough to have a shot into the green, then drained a 50-footer for the birdie.
"It's just a fickle course," he said. "You don't want to get too exotic. If the wind blows, it's tough."
On a crowded leaderboard, England's Ian Poulter and Americans Ricky Barnes, Sean O'Hair and Lucas Glover shared seventh on 138.
Fijian veteran Vijay Singh fired a one-under 70 for 139, where he was joined by Michael Putnam, Jason Bohn and Justin Thomas.
Overnight leader Brian Davis of England struggled to a 76 that left him tied for 28th on one-under 141.
World number four Adam Scott of Australia fired a four-over 75 and missed the cut by three strokes - his first missed cut since the 2012 Byron Nelson Championship.
Leading second-round scores on Friday in the PGA Tour $5.9 million
Valspar Championship (USA unless noted, par-71) at Palm Harbour,
136 - Brendon de Jonge (ZIM) 67-69
137 - Jordan Spieth 70-67, Henrik Stenson (SWE) 67-70, Ryan Moore 69-68, Derek Ernst 67-70, Kevin Streelman 68-69
138 - Ricky Barnes 66-72, Ian Poulter (ENG) 68-70, Sean O'Hair 66-72, Lucas Glover 69-69
139 - Michael Putnam 70-69, Jason Bohn 70-69, Justin Thomas 67-72, Vijay Singh (FIJ) 69-70
- Matt Kuchar 70-70, Luke Donald (ENG) 72-68, Alex Cejka (GER) 67-73,
Cameron Tringale 71-69, Billy Hurley 69-71, Nick Taylor (CAN) 70-70,
Patrick Reed 72-68, Ken Duke 73-67, Brendon Todd 70-70, Charles Howell
70-70, Shawn Stefani 68-72, Russell Knox (SCO) 69-71