Gullane -England's Daniel Brooks was a surprise halfway-stage leader of the Scottish Open at Gullane on Friday, getting to 11-under par on the back of a second round of 65.
Ranked 528th in the world, the 28-year-old played a second straight superb round of golf to leave a top-class field trailing in his wake.
Brooks leads by three strokes over a six-strong group including world number seven and defending champion Justin Rose, Irish links specialist Shane Lowry, back-to-form Graeme McDowell, all of whom had 66s, and leading American challenger Ryan Palmer with a 65.
A further stroke back on seven under came Rafa Cabrera-Bello of Spain (66), Argentina's Emiliano Grillo (67) and English trio Tommy Fleetwood (66), Richard McEvoy (67) and Richard Finch (68).
The tournament on East Lothian's Golf Coast is a prime buildup event for next week's British Open at nearby St Andrews, but as it stands, Brooks has not even qualified for that.
To do so he would have to finish in the top 10 come Sunday evening and his play over the first two rounds have certainly given him every chance to do so.
Brooks has won just once on the European Tour - at the 2014 Madeira Islands Open - and that 36-hole victory was totally overshadowed by the tragic death of Alastair Forsyth's caddie Ian McGregor.
His recent form has been poor, but a strong showing at last week's French Open did wonders for his confidence and he came in late Thursday with a 64 to sit alone in second.
Friday's round was draped around an eagle at the second, where he hit a five-iron to eight feet, and birdies at the final two holes.
"It seems like a long time ago now (Madeira Islands win). I played some terrible golf between now and then, but I'm starting to come back," he said.
"It's hard, you know, to miss that many cuts. It does get you down. It only takes one good week out here and hopefully that's what I'll have."
Rose's second straight 66 put him into prime position for a successful defence of the Scottish Open crown he won last year at Aberdeen.
The 34-year-old Englishman went out in 31 before parring his way down the relatively tougher back nine on the par-70 course which is a composite of the number one and two courses on the East Lothian links.
No player has ever won back-to-back Scottish Open titles and, were Rose to achieve that feat on Sunday, it would underline his position among the favourites at St Andrews in the absence of injured world number one Rory McIlroy.
Despite the low scores, Rose assessed his game as only "running at 50 per cent", adding: "There are still a couple of loose shots that I am getting away with on this course that I wouldn't on other courses.
"But I feel like I have managed my game well, played the hard holes well and kept it clean."
The 2013 US Open winner had a scary moment at the 16th when his tee shot struck an elderly spectator on the head, which led to a teenage fan fainting at the sight of the resulting blood.
Rose's playing partner, Phil Mickelson, who won the 2013 Open just down the road at Muirfield, could only manage one birdie on the front nine and bogeys at 10 and 11 saw him flirting with the projected cut after 77 players broke par on Thursday.
But a run of three straight birdies from the 14th proved to be a timely tonic and he came in with a 68 to stand at three under for the tournament.
Other American invaders, Rickie Fowler and Matt Kuchar, were both on six under with Jimmy Walker a shot worse off.
First round leader Thorbjorn Olesen collapsed, following up his 63 with a 77 that meant he missed the cut.
McDowell's second straight 66 confirmed he is enjoying being back playing the form of seaside golf he grew up with after a miserable first half of the season.
Low-scoring was again the order of the day with calm conditions prevailing and the greens remaining soft and receptive.
Round 2 leaderboard:
129 - Daniel Brooks (ENG) 64-65
132 - Ryan Palmer (USA) 67-65, Graeme McDowell (NIR) 66-66, Shane Lowry (IRL) 66-66, Justin Rose (ENG) 66-66, Mathew Nixon (ENG) 65-67, Johan Carlsson (SWE) 65-67
133 - Tommy Fleetwood (ENG) 67-66, Rafa Cabrera-Bello (ESP) 67-66, Emiliano Grillo (ARG) 67-66, Richard McEvoy (ENG) 66-67, Richard Finch (ENG) 65-68
134 - Maximilian Kiefer (GER) 69-65, Joost Luiten (NED) 71-63, Miguel Angel Jimenez (ESP) 69-65, Paul Lawrie (SCO) 69-67, Andrew Johnston (ENG) 67-67, Rickie Fowler (USA) 66-68, Matt Kuchar (USA) 66-68, Gary Stal (FRA) 66-68, Gregory Havret (FRA) 66-68, Seve Benson (ENG) 65-69
135 - Ross Fisher (ENG) 70-65, Michael Hoey (NIR) 70-65, Branden Grace (RSA) 69-66, Ben Martin (USA) 69-66, Jaco Van Zyl (RSA) 69-66, Raphael Jacquelin (FRA) 68-67, Y.E Yang (KOR) 68-67, Cameron Tringale (USA) 68-67, Russell Knox (SCO) 67-68, Jimmy Walker (USA) 65-70